Topical composition and delivery system and its use

ABSTRACT

The described invention provides a topical delivery system comprising a pharmaceutical composition for application directly to a skin of a subject in need thereof comprising (a) an effective therapeutic amount of an active therapeutic agent; (b) chemical drivers comprising an amino benzoate local anesthetic, ethoxydiglycol and methylsulfonylmethane (MSM) that in combination are effective to synergistically deliver the therapeutic agent; and (c) a depot component for keeping the pharmaceutical composition in the skin. Methods for delivering an active therapeutic agent into skin, for keeping it in the skin, for reducing systemic side effects attributable to entry of the active agent into the blood stream, and a method for treating a condition, disease or disorder of skin topically also are described in accordance with the embodiments of the described invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. application Ser.No. 14/098,633 (filed Dec. 6, 2013), which claims the benefit ofpriority to provisional application 61/734,748 (filed Dec. 7, 2012) and61/765,115 (filed Feb. 15, 2013). Each of these applications isincorporated herein by reference.

FIELD OF THE INVENTION

The described invention relates to topical formulations of apharmaceutical compositions containing an active therapeutic agent ormetabolite, and a delivery system for administering the same topically,characterized in that the active(s) remain in the skin and penetrationof the active(s) into the bloodstream is limited so as to reducesystemic side effects.

BACKGROUND OF THE INVENTION

1. Anatomy and Physiology of the Skin

The skin is the largest organ in the body consisting of several layersand plays an important role in biologic homeostasis, and is comprised ofthe epidermis and the dermis. The epidermis, which is composed ofseveral layers beginning with the stratum corneum, is the outermostlayer of the skin, and the innermost skin layer is the deep dermis. Theskin has multiple functions, including thermal regulation, metabolicfunction (vitamin D metabolism), and immune functions. FIG. 1 presents adiagram of skin anatomy.

In humans, the usual thickness of the skin is from 1-2 mm, althoughthere is considerable variation in different parts of the body. Therelative proportions of the epidermis and dermis also vary, and a thickskin is found in regions where there is a thickening of either or bothlayers. For example, on the interscapular (between the shoulder blades)region of the back, where the dermis is particularly thick, the skin maybe more than 5 mm thick, whereas on the eyelids it may be less than 0.5mm. Generally, the skin is thicker on the dorsal or extensor surfaces ofthe body than on the ventral or flexor surfaces; however, this is notthe case for the hands and feet. The skin of the palms and soles isthicker than on any dorsal surface except the intrascapular region. Thepalms and soles have a characteristically thickened epidermis, inaddition to a thick dermis.

The entire skin surface is traversed by numerous fine furrows, which runin definite directions and cross each other to bound small rhomboid orrectangular fields. These furrows correspond to similar ones on thesurface of the dermis so that, in section, the boundary line betweenepidermis and dermis appears wavy. On the thick skin of the palms andsoles, the fields form long, narrow ridges separated by parallelcoursing furrows, and in the fingertips these ridges are arranged in thecomplicated loops, whorls (verticil) and spirals that give thefingerprints characteristic for each individual. These ridges are moreprominent in those regions where the epidermis is thickest.

Where there is an epidermal ridge externally there is a correspondingnarrower projection, called a “rete peg,” on the dermal surface. Dermalpapillae on either side of each rete peg project irregularly into theepidermis. In the palms and soles, and other sensitive parts of theskin, the dermal papillae are numerous, tall and often branched, andvary in height (from 0.05 mm to 0.2 mm). Where mechanical demands areslight and the epidermis is thinner, such as on the abdomen and face,the papillae are low and fewer in number.

Epidermis

The epidermis provides the body's buffer zone against the environment.It provides protection from trauma, excludes toxins and microbialorganisms, and provides a semi-permeable membrane, keeping vital bodyfluids within the protective envelope. Traditionally, the epidermis hasbeen divided into several layers, of which two represent the mostsignificant ones physiologically. The basal-cell layer, or germinativelayer, is of importance because it is the primary source of regenerativecells. In the process of wound healing, this is the area that undergoesmitosis in most instances. The upper epidermis, including stratum andgranular layer, is the other area of formation of the normalepidermal-barrier function.

Stratum Corneum and the Acid Mantle

Stratum corneum is an avascular, multilayer structure that functions asa barrier to the environment and prevents transepidermal water loss.Recent studies have shown that enzymatic activity is involved in theformation of an acid mantle in the stratum corneum. Together, the acidmantle and stratum corneum make the skin less permeable to water andother polar compounds, and indirectly protect the skin from invasion bymicroorganisms. Normal surface skin pH is between 4 and 6.5 in healthypeople; it varies according to area of skin on the body. This low pHforms an acid mantle that enhances the skin barrier function.

Other Layers of the Epidermis

Other layers of the epidermis below the stratum corneum include thestratum lucidum, stratum granulosum, stratum germinativum, and stratumbasale. Each contains living cells with specialized functions (FIG. 2).For example melanin, which is produced by melanocytes in the epidermis,is responsible for the color of the skin. Langerhans cells are involvedin immune processing.

Dermal Appendages

Dermal appendages, which include hair follicles, sebaceous and sweatglands, fingernails, and toenails, originate in the epidermis andprotrude into the dermis hair follicles and sebaceous and sweat glandscontribute epithelial cells for rapid reepithelialization of wounds thatdo not penetrate through the dermis (termed partial-thickness wounds).The sebaceous glands are responsible for secretions that lubricate theskin, keeping it soft and flexible. They are most numerous in the faceand sparse in the palm of the hands and soles of the feet. Sweat glandsecretions control skin pH to prevent dermal infections. The sweatglands, dermal blood vessels, and small muscles in the skin (responsiblefor goose pimples) control temperature on the surface of the body. Nerveendings in the skin include receptors for pain, touch, heat, and cold.Loss of these nerve endings increases the risk for skin breakdown bydecreasing the tolerance of the tissue to external forces.

The basement membrane both separates and connects the epidermis anddermis. When epidermal cells in the basement membrane divide, one cellremains, and the other migrates through the granular layer to thesurface stratum corneum. At the surface, the cell dies and formskeratin. Dry keratin on the surface is called scale. Hyperkeratosis(thickened layers of keratin) is found often on the heels and indicatesloss of sebaceous gland and sweat gland functions if the patient isdiabetic. The basement membrane atrophies with aging; separation betweenthe basement membrane and dermis is one cause for skin tears in theelderly.

Dermis

The dermis, or the true skin, is a vascular structure that supports andnourishes the epidermis. In addition, there are sensory nerve endings inthe dermis that transmit signals regarding pain, pressure, heat, andcold. The dermis is divided into two layers: the superficial dermis andthe deep dermis.

The superficial dermis consists of extracellular matrix (collagen,elastin, and ground substances) and contains blood vessels, lymphatics,epithelial cells, connective tissue, muscle, fat, and nerve tissue. Thevascular supply of the dermis is responsible for nourishing theepidermis and regulating body temperature. Fibroblasts are responsiblefor producing the collagen and elastin components of the skin that giveit turgor. Fibronectin and hyaluronic acid are secreted by thefibroblasts. The structural integrity of the dermis plays a role in thenormal function and youthful appearance of the skin.

The deep dermis is located over the subcutaneous fat; it contains largernetworks of blood vessels and collagen fibers to provide tensilestrength. It also consists of fibroelastic connective tissue, which isyellow and composed mainly of collagen. Fibroblasts are also present inthis tissue layer. The well-vascularized dermis withstands pressure forlonger periods of time than subcutaneous tissue or muscle. The collagenin the skin gives the skin its toughness. Dermal wounds, e.g., cracks orpustules, involve the epidermis, basal membrane, and dermis. Typically,dermal injuries heal rapidly.

2. Effects of Application to the Skin

Substances are applied to the skin to elicit one or more of four generaleffects: an effect on the skin surface, an effect within the stratumcorneum; an effect requiring penetration into the epidermis and dermis;or a systemic effect resulting from delivery of sufficient amounts of agiven substance through the epidermis and the dermis to the vasculatureto produce therapeutic systemic concentrations. One example of an effecton the skin surface is formation of a film. Film formation may beprotective (e.g., sunscreen) and/or occlusive (e.g., to provide amoisturizing effect by diminishing loss of moisture from the skinsurface). One example of an effect within the stratum corneum is skinmoisturization; which may involve the hydration of dry outer cells bysurface films or the intercalation of water in the lipid-richintercellular laminae; the stratum corneum also may serve as a reservoirphase or depot wherein topically applied substances accumulate due topartitioning into, or binding with, skin components.

It generally is recognized that short-term penetration occurs throughthe hair follicles and the sebaceous apparatus of the skin, while longterm penetration occurs across cells. Penetration of a substance intothe viable epidermis and dermis may be difficult to achieve, but once ithas occurred, the continued diffusion of the substance into the dermisis likely to result in its transfer into the microcirculation of thedermis and then into the general circulation. It is possible, however,to formulate delivery systems that provide substantial localizeddelivery.

Percutaneous absorption is the absorption of substances from outside theskin to positions beneath the skin, including into the blood stream. Theepidermis of human skin is highly relevant to absorption rates. Passagethrough the stratum corneum marks the rate-limiting step forpercutaneous absorption. The major steps involved in percutaneousabsorption of, for example, a drug, include the establishment of aconcentration gradient, which provides a driving force for drug movementacross the skin, the release of drug from the vehicle into theskin-partition coefficient and drug diffusion across the layers of theskin-diffusion coefficient. The relationship of these factors to oneanother is summarized by the following equation:J=Cveh×Km·D/x  [Formula 1]

where J=rate of absorption; Cveh=concentration of drug in vehicle;Km=partition coefficient; and D=diffusion coefficient.

The many factors that affect the rate of percutaneous absorption of asubstance include, without limitation, the following: (i) Concentration.The more concentrated the substance, the greater the absorption rate.(ii) Size of skin surface area. The wider the contact area of the skinto which the substance is applied, the greater the absorption rate.(iii) Anatomical site of application. Skin varies in thickness indifferent areas of the body. A thicker and more intact stratum corneumdecreases the rate of absorbency of a substance. The stratum corneum ofthe facial area is much thinner than, for example, the skin of the palmsof the hands. The facial skin's construction and the thinness of thestratum corneum provide an area of the body that is optimized forpercutaneous absorption to allow delivery of active agents both locallyand systemically through the body. (iv) Hydration. Hydration (meaningincreasing the water content of the skin) causes the stratum corneum toswell which increases permeability. (v) Skin temperature. Increased skintemperature increases permeability. (vi) Composition. The composition ofthe compound and of the vehicle also determines the absorbency of asubstance.

Most substances applied topically are incorporated into bases orvehicles. The vehicle chosen for a topical application will greatlyinfluence absorption, and may itself have a beneficial effect on theskin. Factors that determine the choice of vehicle and the transfer rateacross the skin are the substance's partition coefficient, molecularweight and water solubility. The protein portion of the stratum corneumis most permeable to water soluble substances and the lipid portion ofthe stratum corneum is most permeable to lipid soluble substances. Itfollows that substances having both lipid and aqueous solubility maytraverse the stratum corneum more readily. (See Dermal ExposureAssessment: Principles and Applications, EPA/600/8-91/011b, January1992, Interim Report—Exposure Assessment Group, Office of Health andEnvironmental Assessment, U.S. Environmental Protection Agency,Washington, D.C. 20460).

3. Wound Healing

The term “wound healing” refers to the process by which the body repairstrauma to any of its tissues, especially those caused by physical meansand with interruption of continuity. The term “wound healing agent”refers to any substance that facilitates the wound healing process.

A wound-healing response often is described as having three distinctphases-injury, inflammation and repair. Generally speaking, the bodyresponds to injury with an inflammatory response, which is crucial tomaintaining the health and integrity of an organism. If however it goesawry, it can result in tissue destruction.

Phase I: Injury

Injury caused by factors including, but not limited to, autoimmune orallergic reactions, environmental particulates, infection or mechanicaldamage often results in the disruption of normal tissue architecture,initiating a healing response. Damaged epithelial and endothelial cellsmust be replaced to maintain barrier function and integrity and preventblood loss, respectively. Acute damage to endothelial cells leads to therelease of inflammatory mediators and initiation of an anti-fibrinolyticcoagulation cascade, temporarily plugging the damaged vessel with aplatelet and fibrin-rich clot.

Platelet recruitment, degranulation and clot formation rapidly progressinto a phase of vasoconstriction with increased permeability, allowingthe extravasation (movement of white blood cells from the capillaries tothe tissues surrounding them) and direct recruitment of leukocytes tothe injured site. The basement membrane, which forms the extracellularmatrix underlying the epithelium and endothelium of parenchymal tissue,precludes direct access to the damaged tissue. To disrupt this physicalbarrier, zinc-dependent endopeptidases, also called matrixmetalloproteinases (MMPs), cleave one or more extracellular matrixconstituents allowing extravasation of cells into, and out of, damagedsites. Specifically, MMP-2 (gelatinase A, Type N collagenase) and MMP-9(gelatinase B, Type IV collagenase) cleave type N collagens and gelatin,two important constituents of the basement membrane. Recent studies havefound that MMP-2 and MMP-9 are upregulated, highlighting thattissue-destructive and regenerative processes are common in fibroticconditions. The activities of MMPs are controlled by several mechanismsincluding transcriptional regulation, proenzyme regulation, and specifictissue inhibitors of MMPs. The balance between MMPs and the variousinhibitory mechanisms can regulate inflammation and determine the netamount of collagen deposited during the healing response.

Phase II: Inflammation

Once access to the site of tissue damage has been achieved, chemokinegradients recruit inflammatory cells. Neutrophils, eosinophils,lymphocytes, and macrophages are observed at sites of acute injury withcell debris and areas of necrosis cleared by phagocytes.

The early recruitment of eosinophils, neutrophils, lymphocytes, andmacrophages providing inflammatory cytokines and chemokines cancontribute to local TGF-β and IL-13 accumulation. Following the initialinsult and wave of inflammatory cells, a late-stage recruitment ofinflammatory cells may assist in phagocytosis, in clearing cell debris,and in controlling excessive cellular proliferation, which together maycontribute to normal healing. Late-stage inflammation may serve ananti-fibrotic role and may be required for successful resolution ofwound-healing responses. For example, a late-phase inflammatory profilerich in phagocytic macrophages, assisting in fibroblast clearance, inaddition to IL-10-secreting regulatory T cells, suppressing localchemokine production and TGF-β, may prevent excessive fibroblastactivation.

The nature of the insult or causative agent often dictates the characterof the ensuing inflammatory response. For example, exogenous stimulilike pathogen-associated molecular patterns (PAMPs) are recognized bypathogen recognition receptors, such as toll-like receptors and NOD-likereceptors (cytoplasmic proteins that have a variety of functions inregulation of inflammatory and apoptotic responses), and influence theresponse of innate cells to invading pathogens. Endogenous dangersignals also can influence local innate cells and orchestrate theinflammatory cascade.

The nature of the inflammatory response dramatically influences residenttissue cells and the ensuing inflammatory cells. Inflammatory cellsthemselves also propagate further inflammation through the secretion ofchemokines, cytokines, and growth factors. Many cytokines are involvedthroughout a wound-healing and fibrotic response, with specific groupsof genes activated in various conditions.

Phase III: Tissue Repair and Contraction

The closing phase of wound healing consists of an orchestrated cellularre-organization guided by a fibrin (a fibrous protein that ispolymerized to form a “mesh” that forms a clot over a wound site)-richscaffold formation, wound contraction, closure and re-epithelialization.The vast majority of studies elucidating the processes involved in thisphase of wound repair have come from dermal wound studies and in vitrosystems.

Myofibroblast-derived collagens and smooth muscle actin (α-SMA) form aprovisional extracellular matrix, with macrophage, platelet, andfibroblast-derived fibronectin forming a fibrin scaffold. Collectively,these structures are commonly referred to as granulation tissues.

In addition to fibronectin, the provisional extracellular matrixconsists of glycoproteins (such as PDGF), glycosaminoglycans (such ashyaluronic acid), proteoglycans and elastin. Growth factor andTGF-β-activated fibroblasts migrate along the extracellular matrixnetwork and repair the wound. Within skin wounds, TGF-β also induces acontractile response, regulating the orientation of collagen fibers.Fibroblast to myofibroblast differentiation, as discussed above, alsocreates stress fibers and the neo-expression of α-SMA, both of whichconfer the high contractile activity within myofibroblasts. Theattachment of myofibroblasts to the extracellular matrix at specializedsites called the “fibronexus” or “super mature focal adhesions” pull thewound together, reducing the size of the lesion during the contractionphase. The extent of extracellular matrix laid down and the quantity ofactivated myofibroblasts determines the amount of collagen deposition.To this end, the balance of matrix metalloproteinases (MMPs) to tissueinhibitor of metalloproteinases (TIMPs) and collagens to collagenasesvary throughout the response, shifting from pro-synthesis and increasedcollagen deposition towards a controlled balance, with no net increasein collagen. For successful wound healing, this balance often occurswhen fibroblasts undergo apoptosis, inflammation begins to subside, andgranulation tissue recedes, leaving a collagen-rich lesion. From skinstudies, re-epithelialization of the wound site re-establishes thebarrier function and allows encapsulated cellular re-organization.Several in vitro and in vivo models, using human or rat epithelial cellsgrown over a collagen matrix, or tracheal wounds in vivo, have been usedto identify significant stages of cell migration, proliferation, andcell spreading. Rapid and dynamic motility and proliferation, withepithelial restitution from the edges of the denuded area occur withinhours of the initial wound. In addition, sliding sheets of epithelialcells can migrate over the injured area assisting wound coverage.Several factors have been shown to regulate re-epithelialization,including serum-derived transforming growth factor alpha (TGF-α), andmatrix metalloproteinase-7 (MMP-7) (which itself is regulated byTIMP-1).

4. Delivery Systems for Topical Administration

Many active agents are administrated enterally or parenterally. Enteralroutes of administration involve administration to any part of thegastrointestinal tract, typically via oral forms, e.g., pills, tablets,emulsions, and syrups, or via rectal forms, e.g., enemas, Murphy drips,and suppositories. Parenteral routes of administration involveadministration by some means other than oral or rectal, typically viainjection. While such administration routes allow for accurate andconsistent dosing, such routes necessarily yield systemic effects, e.g.,vestibular symptoms, headache and general malaise, and gastrointestinalsymptoms, which in certain circumstances are not desirable.

Topical routes of administration involve administration to a bodysurface, such as the skin, or mucous membranes. Many forms of topicaladministration involve applying a therapeutic agent directly to theskin; inhalable mediations, eye drops, and ear-drops also are consideredtopical administration forms. Although topical administration generallyprovides a local effect, many topically administered drugs likewise canexhibit systemic effects, such as vestibular symptoms (e.g., vertigo,dizziness or blurred vision), headache and general malaise,gastro-intestinal symptoms, such as diarrhea, nausea, gas, cramps, drynose and dry mouth.

Formulations for topical application can take the compositional form ofa liquid, a semisolid dosage form (e.g., a paste, a cream, a lotion, apowder, an ointment or a gel) or a patch.

Liquid formulations do not readily stay in place and can be messy.Semisolid formulations offer some advantages characteristic of topicaladministration, such as ease of application, and increased local dosesof active agent, with reduced systemic effects, but their potentialdisadvantages include the need for repeated application, difficulties inaccurate dosing, and messy or unattractive cosmetic attributes, all ofwhich can lead to poor user compliance, and unintentional removal ortransfer of active agent via contact with objects or other persons.

Topical patches, which are available in multiple forms including singleand multi-layer drug-in-adhesive forms, matrix forms, and reservoirforms, address several of the shortcomings of semisolid formulations,for example, reducing the need for repeated application, providingaccurate, and controlled release of active agent, and reducing thelikelihood of unintentional removal or transfer of drug or active agentvia contact with objects or other persons, but have a finite size andshape. Because topical patches have a finite size and shape, theapplication area is determined by the dimensions of the patch ratherthan the dimensions of the affected site. Accordingly, it may benecessary to use a number of patches in order to cover a large affectedsite. Furthermore, topical patches typically lack sufficient flexibilityto be effectively administered to joints or other areas of skin subjectto significant stretching movements. Topical patches can also lead touser discomfort, particular in warmer climates, and can be aestheticallyunpleasing, which can also lead to poor user compliance.

A number of attempts have been made for delivering therapeuticformulations topically. One common problem inherent to topicalformulations that has been experienced thus far has been to control thetherapeutic active agent, as well as the other composition components,such that they are specifically confined in the area of the skin inwhich they have been directly applied. This is turn may result in toofast release of the drug with the consequence of causing undesirablespikes and high levels of the drug in the bloodstream, thereby creatingdeleterious effects such as e.g. unwanted side-effects, wash-out ormetabolism of the drug.

The described invention addresses and overcomes these shortcomings. Thedescribed composition and method provides a safe and effective topicaltherapeutic drug delivery platform that can deliver drugs locally intothe skin. The described invention is effective to deliver the componentsof the pharmaceutical formulation into the skin, to keep them in theskin, and to reduce the potential of the active therapeutic agent or itsmetabolites to enter the bloodstream. Consequently, the activetherapeutic agent executes its effective biological function locally atthe tissue of interest once being released from the skin.

SUMMARY OF THE INVENTION

According to one aspect, the described invention provides a topicaldelivery system comprising a pharmaceutical composition for applicationdirectly to a skin of a subject in need thereof comprising (a) atherapeutic amount of an active therapeutic agent to treat symptoms of adisease, disorder or condition; (b) chemical drivers comprising an aminobenzoate local anesthetic, ethoxydiglycol and methylsulfonylmethane,wherein the chemical drivers are effective at acting synergistically todeliver the therapeutic agent and (c) a depot component that iseffective to keep the active agent locally in the skin; to reducedistribution of the active agent to the blood stream; to encapsulate thepharmaceutical composition and to facilitate controlled or delayed typerelease of the active therapeutic agent. According to some embodiments,the active therapeutic agent has a molecular weight below 500 Da.According to some embodiments, the active therapeutic agent is selectedfrom the group consisting of a steroidal or non-steroidal analgesicagent, a wound healing agent, an antihistamine and an anti-neoplasticagent. According to some embodiments the amino benzoate local anestheticis selected from the group consisting of benzocaine, lidocaine,tetracaine or a combination thereof. According to some embodiments, thepharmaceutical composition is in an administration form selected fromthe group consisting of a cream, gel, or a spray. According to someembodiments, the topical delivery system further comprises avasoconstrictor. According to some embodiments, the vasoconstrictor isnonirritating when applied to skin. According to some embodiments, thedepot component is a liposome. According to some embodiments, theliposome comprises a phosphatidyl choline, cholesterol, and apharmaceutically acceptable salt of an active therapeutic agent and atleast one anionic or cationic phospholipid. According to someembodiments, the depot component comprises a polymer. According to someembodiments, the depot component comprises a liposome and a polymer.According to some embodiments, the depot component comprises apolymersome.

According to another aspect, the described invention provides a methodof delivering a pharmaceutical composition topically that is effectiveto reduce systemic side effects of the active agent comprising (a)applying a pharmaceutical composition to a skin of a subject in needthereof, wherein the pharmaceutical composition comprises: (i) achemical driver effective to penetrate the stratum corneum of skincontaining an active therapeutic agent, wherein the active therapeuticagent is an amino benzoate local anesthetic; ethoxydiglycol andmethylsulfonylmethane (MSM); and (ii) a depot component that iseffective to keep the pharmaceutical composition in the skin and tominimize distribution systemically. According to some embodiments, theactive therapeutic agent has a molecular weight below 500 Da. Accordingto some embodiments, the active therapeutic agent does not get into thebloodstream. According to some embodiments, the depot component of thecomposition is effective to facilitate controlled or delayed typerelease of the active therapeutic agent. According to some embodiments,the depot component is a polymer. According to other embodiments, thedepot component is a liposome. According to some embodiments, theliposome comprises a phosphatidyl choline, cholesterol and apharmaceutically acceptable salt of an active therapeutic agent and atleast one anionic or cationic phospholipid. According to someembodiments, the depot component comprises a liposome and a polymer.According to other embodiments, the depot component is a polymersome.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a diagram of skin anatomy. Taken from Stedman's MedicalDictionary, 27th Ed., Lippincott, Williams & Wilkins, Baltimore, Md.(2000), at 1647.

FIG. 2 depicts layers of the epidermis.

FIG. 3 shows the study schema for the Phase I Clinical Study fordetermining the uptake kinetics of NeuroMed 7™ pain relief creamcomposed of lidocaine HCl 4% w/w in base formula with dosing at 0 and 4hours, and self-reported visual analog scale (VAS); and venous blooddraws at 0 (baseline), 1, 3, 5, 7, 9 and 11 hours.

FIG. 4 shows the percentage of pain reduction for the study subjects.

FIG. 5 shows the average pain reduction for the study subjects.

FIG. 6 shows the maximal pain reduction for the study subjects.

FIG. 7 shows the time of maximum pain relief for the study subjects.

DETAILED DESCRIPTION OF THE INVENTION Glossary

The term “active therapeutic agent” as used herein refers to a drug,molecule, nucleic acid, protein, composition or other substance thatprovides a therapeutic effect. The term “active” as used herein refersto the ingredient, component or constituent of the compositions of thedescribed invention responsible for the intended therapeutic effect. Theterms “therapeutic agent” and “active agent” are used interchangeably.

The term “administer” as used herein means to give or to apply. The term“administering” as used herein includes in vivo administration, as wellas administration directly to tissue ex vivo.

The term “alginate” as used herein is an anionic biopolymers produced bya variety of microorganisms and marine algae. Alginate is apolysaccharide that comprises β-D-mannuronic acid units andα-L-guluronic acid units. Some alginate polymers are block copolymerswith blocks of the guluronic acid (or salt) units alternating withblocks of the mannuronic acid (or salt) units. Some alginate moleculeshave single units of guluronic acid (or salt) alternating with singleunits of mannuronic acid (or salt). The ratio and distribution of themannuronic and guluronic unit, along with the average molecular weight,affect the physical and chemical properties of the copolymer. See Haug,A. et al., Acta Chem. Scand., 183-90 (1966). Alginate polymers haveviscoelastic rheological properties and other properties that make itsuitable for some medical applications. See Klock, G. et al.,“Biocompatibility of mannuronic acid-rich alginates,” Biomaterials, Vol.18, No. 10, 707-13 (1997).

The term “analgesic” as used herein refers to any member of a group ofdrugs used to provide relief from pain. “Analgesic agents” act invarious ways on the peripheral and central nervous systems, and aredistinct from “anesthetic agents.

The term “analog” as used herein refers to a compound having a structuresimilar to another, but differing from it, for example, in one or moreatoms, functional groups, or substructure.

The term “anesthetic agent” as used herein refers to an agent thatreversibly produces a reduction or loss of sensation.

The term “anionic lipid” as used herein refers to a lipid which has anegative charge. Exemplary anionic lipids include, without limitation,diacylglycerolhemisuccinates, e.g. DOGS, DMGS, POGS, DPGS, DSGS;diacylglycerolhemimalonates, e.g. DOGM or DMGM;diacylglycerolhemiglutarates, e.g. DOGG, DMGG;diacylglycerolhemiadipates, e.g. DOGA, DMGA;diacylglycerolhemicyclohexane-1,4-dicarboxylic acids, e.g. DO-cHA,DM-cHA; (2, 3-Diacyl-propyl)amino}-oxoalkanoic acids e.g. DOAS, DOAM,DOAG, DOAA, DMAS, DMAM, DMAG, DMAA; Diacyl-alkanoic acids, e.g. DOP,DOB, DOS, DOM, DOG, DOA, DMP, DOB, DMS, DMM, DMG, DMA; Chemicals andderivatives thereof, e.g. Chol-C2, Chol-C3, Chol-C5, Chol-C6, Chol-C7 orChol-C8; Chol-CI, CholC3N or Cholesterolhemidicarboxylic acids andCholesteryloxycarbonylaminocarboxylic acids, e.g. Chol-C12 or CholC13N,fatty acids, e.g. Oleic acid, Myristic Acid, Palmitic acid, Stearicacid, Nervonic Acid, Behenic Acid; DOPA, DMPA, DPPA, POPA, DSPA,Chol-S04, DOPG, DMPG, DPPG, POPG, DSPG or DOPS, DMPS, DPPS, POPS, DSPSor Cetyl-phosphate.

The aforementioned lipids may be formed with or without cholesterol, orwith a derivative of cholesterol (e.g., cholesterol sulfate).

The terms “anti-neoplastic agent”, “anticancer agent” or“chemotherapeutic agent” are used interchangeably to refer to an agentthat inhibits growth, proliferation, and spread of a neoplasm.Non-limiting examples of anti-neoplastic agents include 5-fluorouracil,adriamycin, daunorubicin, cytarabine, vincristine, actinomycin D,mitomycin, bleomycin, acrarubicin, and combinations thereof. Accordingto some embodiments, the anti-neoplastic agent can be entrapped in alysosome. For the antineoplastic agent to be entrapped in the liposomesaccording to the invention, any such agent can be selected, provided theagent does not inhibit liposome formation.

The term “antihistamine agent” as used herein refers to any of variouscompounds that counteract histamine in the body and that are used fortreating allergic reactions (such as hay fever) and cold symptoms.Non-limiting examples of antihistamines usable in context of thedescribed invention include chlorpheniramine, brompheniramine,dexchlorpheniramine, tripolidine, clemastine, diphenhydramine,promethazine, piperazines, piperidines, astemizole, loratadine andterfenadine.

As used herein the term “anti-inflammatory agent” refers to atherapeutic agent that counteracts and inhibits the process ofinflammation and swelling. The term “non-steroidal anti-inflammatoryagent” as used herein refers to a large group of agents that areaspirin-like in their action, including, but not limited to, ibuprofen(Advil®), naproxen sodium (Aleve®), and acetaminophen (Tylenol®).Additional examples of non-steroidal anti-inflammatory agents that areusable in the context of the described invention include, withoutlimitation, oxicams, such as piroxicam, isoxicam, tenoxicam, sudoxicam,and CP-14,304; disalcid, benorylate, trilisate, safapryn, solprin,diflunisal, and fendosal; acetic acid derivatives, such as diclofenac,fenclofenac, indomethacin, sulindac, tolmetin, isoxepac, furofenac,tiopinac, zidometacin, acematacin, fentiazac, zomepirac, clindanac,oxepinac, felbinac, and ketorolac; fenamates, such as mefenamic,meclofenamic, flufenamic, niflumic, and tolfenamic acids; propionic acidderivatives, such as benoxaprofen, flurbiprofen, ketoprofen, fenoprofen,fenbufen, indopropfen, pirprofen, carprofen, oxaprozin, pranoprofen,miroprofen, tioxaprofen, suprofen, alminoprofen, and tiaprofenic;pyrazoles, such as phenylbutazone, oxyphenbutazone, feprazone,azapropazone, and trimethazone. Mixtures of these non-steroidalanti-inflammatory agents also may be employed, as well as thedermatologically acceptable salts and esters of these agents. Oneexample is etofenamate, a flufenamic acid derivative.

The term “anti-oxidant agent” as used herein refers to a substance thatinhibits oxidation or reactions promoted by oxygen or peroxides.Non-limiting examples of anti-oxidants include ascorbic acid (vitamin C)and its salts, ascorbyl esters of fatty acids, ascorbic acid derivatives(e.g., magnesium ascorbyl phosphate, sodium ascorbyl phosphate, ascorbylsorbate), tocopherol (vitamin E), tocopherol sorbate, tocopherolacetate, other esters of tocopherol, butylated hydroxy benzoic acids andtheir salts, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid(commercially available under the tradename TroloxR), gallic acid andits alkyl esters, especially propyl gallate, uric acid and its salts andalkyl esters, sorbic acid and its salts, lipoic acid, amines (e.g.,N,N-diethylhydroxylamine, amino-guanidine), sulfhydryl compounds (e.g.,glutathione), dihydroxy fumaric acid and its salts, glycine pidolate,arginine pilolate, nordihydroguaiaretic acid, bioflavonoids, curcumin,lysine, methionine, proline, superoxide dismutase, silymarin, teaextracts, grape skin/seed extracts, melanin, and rosemary extracts.

The term “anti-static” refers to a compound used to treat materials ortheir surfaces in order to reduce or eliminate buildup of staticelectricity.

The term “apply” as used herein refers to placing in contact with or tolay or spread on.

The term “arabinogalactan” as used herein refers to a wood sugarextracted from the Western Larch tree (also known as larch gum).Arabinogalactans are complex, highly branched polymers of arabinose andgalactose in the ratio of from about 1:3 to about 1:10, i.e., 1:3, 1:4,1:5, 1:6, 1:7, 1:8, 1:9 or 1:10. A commercially available example isLaracare®200 from Lonza, Inc.

The term “bactericide” as used herein refers to a substance that killsbacteria. Bactericides may be disinfectants, antiseptics, antibiotics,etc.

The term “bio-distribution” as used herein refers to a method oftracking where drugs, active therapeutic agents, compounds of interestetc. travel in the subject in need thereof.

The term “buffer” refers to an aqueous solution consisting of a mixtureof a weak acid and its conjugate base, or vice versa. The pH changesvery little when a small or moderate amount of strong acid or base isadded to it, and thus it is used to prevent changes in the pH of asolution.

The term “carrier” as used herein describes a material that does notcause significant irritation to an organism and does not abrogate thebiological activity and properties of the compound of the composition ofthe described invention. Carriers must be of sufficiently high purityand of sufficiently low toxicity to render them suitable foradministration to the mammal being treated. The carrier can be inert, orit can possess pharmaceutical benefits. The terms “excipient”,“carrier”, or “vehicle” are used interchangeably to refer to carriermaterials suitable for formulation and administration ofpharmaceutically acceptable compositions described herein.

The term “cationic lipid” as used herein refers to a lipid which has apositive charge. Exemplary cationic lipids include, without limitation,DOTAP, DMTAP, DPTAP, DSTAP, POTAP, DODAP, PODAP, DMDAP, DPDAP, DSDAP,DODMHEAP or DORI, PODMHEAP or PORI, DMDMHEAP or DMRI, DPDMHEAP or DPRI,DSDMHEAP or DSRI, DOMDHEAP, POMDHEAP, DMMDHEAP, DPMDHEAP, DSMDHEAP,DOMHEAP, POMHEAP, DMMHEAP, DPMHEAP, DSMHEAP, DODHEAP, PODHEAP, DMDHEAP,DPDHEAP, DSDHEAP, DDAB, DODAC, DOEPC, DMEPC, DPEPC, DSEPC, POEPC, DORIE,DMRIE, DOMCAP, DOMGME, D0P5P, D0P6P, DC-Choi, TC-Chol, DAC-Chol,Chol-Betaine, N-methyl-PipChol, CTAB, DOTMA, MoChol, HisChol, Chim,MoC3Chol, Choi-C3N-Mo3, Chol-C3N-Mo2, Choi-C4N-Mo2, Chol-DMC3N-Mo2,CholC4Hex-Mo2, DmC4Mo2, DmC3Mo2, C3Mo2, C3Mo3, C5Mo2, C6Mo2, C8Mo2,C4Mo4, PipC2-Chol, MoC2Chol, PyrroC2Chol, ImC3Chol, PyC2Chol, MoDO,MoDP, DOIM or DPIM.

The term “chemical driver” as used herein refers to a component orcomponents of the formulation of the described invention that providesthe driving force for a drug to diffuse from the vehicle, into andthrough the stratum corneum of the skin. According to some embodiments,the chemical drivers of the described invention synergisticallycooperate to deliver the therapeutic agent.

The term “cholesterol” as used herein refers to a monohydric secondaryalcohol of the cyclopentenophenantrene (4-ring fused) system containingone double bond. According to some embodiments, cholesterol is aliposome component. According to some embodiments, it is useful toenhance incorporation and emulsification of medicinal products in oilsor fats.

The term “colorant” as used herein refers to a substance used to imparta color on a composition to improve the attractiveness of thecomposition and/or to enable easy product identification. Non-limitingexamples of colorants include oil-soluble dyes, oil dispersible dyes,water-soluble dyes, e.g. acid blue 3, acid blue 104, acid green 1, acidgreen 25, acid yellow 3, acid yellow 73 sodium salt, D&C green No. 5, 6,& 8, D&C yellow No. 7, 8, 10, & 11, D&C violet No. 2, FD&C blue No. 1 &2, FD&C green No. 3, FD&C yellow No. 5 & 6, and mixtures thereof.

The term “compatible” as used herein refers to a property of componentsof a composition whereby the components are capable of being combinedwith each other in a manner such that there is no interaction that wouldsubstantially reduce the efficacy of the composition under ordinary useconditions.

The term “component” as used herein refers to a constituent part,element or ingredient.

The terms “composition” and “formulation” are used interchangeablyherein to refer to a product of the described invention that comprisesall active and inert ingredients.

The term “condition” as used herein, refers to a variety of healthstates and is meant to include disorders or diseases caused by anyunderlying mechanism or disorder, injury, and the promotion of healthytissues and organs.

The term “consequence” as used herein refers to an effect, result oroutcome of something that occurred earlier.

The term “contact” and all its grammatical forms as used herein refersto a state or condition of touching or of immediate or local proximity.

The term “controlled release” as used herein refers to a drug-containingformulation in which the manner and profile of drug release from theformulation are controlled. This includes immediate as well asnon-immediate release formulations, with non-immediate releaseformulations including, but not limited to, sustained release anddelayed release formulations. The term “sustained release” (alsoreferred to as “extended release”) is used herein in its conventionalsense to refer to a drug formulation that provides for gradual releaseof a drug over an extended period of time, and that may result insubstantially constant levels of a drug over an extended time period.The term “delayed release” is used herein in its conventional sense torefer to a drug formulation in which there is a time delay betweenadministration of the formulation and the release of the drug therefrom.“Delayed release” may or may not involve gradual release of drug over anextended period of time, and thus may or may not be “sustained release.”The term “long-term” release, as used herein, means that the drugformulation is constructed and arranged to deliver therapeutic levels ofthe active ingredient for at least: 2 hours, 3 hours, 4 hours, hours, 6hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27hours, 28 hours, 29 hours, 30 hours, 31 hours, 32 hours, 33 hours, 34hours, 35 hours, 36 hours, 37 hours, 38 hours, 39 hours, 40 hours, 41hours, 42 hours, 43 hours, 44 hours, 45 hours, 46 hours, 47 hours, 48hours, 49 hours, 50 hours, 51 hours, 52 hours, 53 hours, 54 hours, 55hours, 56 hours, 57 hours, 58 hours, 59 hours, 60 hours, 61 hours, 62hours, 63 hours, 64 hours, 65 hours, 66 hours, 67 hours, 68 hours, 69hours, 70 hours, 71 hours, 72 hours, 73 hours, 74 hours, 75 hours, 76hours, 77 hours, 78 hours, 79 hours, 80 hours, 81 hours, 82 hours, 83hours, 84 hours, 85 hours, 86 hours, 87 hours, 88 hours, 89 hours, 90hours, 91 hours, 92 hours, 93 hours, 94 hours, 95 hours, 96 hours, 97hours, 98 hours, 99 hours, 100 hours, 101 hours, 102 hours, 103 hours,104 hours, 105 hours, 106 hours, 107 hours, 108 hours, 109 hours, 110hours, 111 hours, 112 hours, 113 hours, 114 hours, 115 hours, 116 hours,117 hours, 118 hours, 119 hours, or 120 hours.

The term “copolymer” as used herein refers to a polymer derived frommore than one species of monomer. The term “polymer” refers to a largemolecule, or macromolecule, composed of many repeated subunits. The term“monomer” refers to a molecule that may bind chemically to othermolecules to form a polymer.

The term “derivative” as used herein means a compound that may beproduced from another compound of similar structure in one or moresteps. A derivative of a compound retains at least a degree of thedesired function of the compound. Accordingly, an alternate term for“derivative” may be “functional derivative.” Derivatives can includechemical modifications, such as alkylation, acylation, carbamylation,iodination or any modification that derivatizes the compound. Suchderivatized molecules include, for example, those molecules in whichfree amino groups have been derivatized to form amine hydrochlorides,p-toluene sulfonyl groups, carbobenzoxy groups, t-butyloxycarbonylgroups, chloroacetyl groups or formal groups. Free carboxyl groups canbe derivatized to form salts, esters, amides, or hydrazides. Freehydroxyl groups can be derivatized to form O-acyl or O-alkylderivatives. See, e.g., Methods and Analytical Procedures, ElsevierBiomedical Press, New York (1975).

The term “disease” or “disorder” as used herein refers to an impairmentof health or a condition of abnormal functioning.

The term “drug” as used herein refers to a substance intended for use inthe diagnosis, cure, mitigation, treatment or prevention of disease ordisorder, or to affect the structure or function of the body.

The terms “effective therapeutic amount”, an “amount effective”, or“pharmaceutically effective amount” of one or more of the active agentsis used interchangeably to refer to an amount that is sufficient toprovide the intended benefit of treatment. An effective amount of anactive agent that can be employed according to the described inventiongenerally ranges from about 0.01 mg/kg body weight to about 100 g/kgbody weight. However, dosage levels are based on a variety of factors,including the type of injury, the age, weight, sex, medical condition ofthe patient, the severity of the condition, the route of administration,and the particular active agent employed. Thus the dosage regimen mayvary widely, but can be determined routinely by a physician usingstandard methods.

The terms “emollient” or “moisturizer” as used herein are usedinterchangeably to refer to complex mixtures of chemical agentsspecially designed to make the external layers of the skin (epidermis)softer and more pliable. An emollient increases the skin's hydration(water content) by reducing evaporation.

The term “emulsifier” as used herein refers to an additive that help twoliquids mix. For example, water and oil separate in a glass, but addingan emulsifier will help the water and oil to mix together.

The term “excipient” as used herein refers to any inactive ingredientthat is added to the composition of the described invention and that isnot intended to exert therapeutic effects at the intended dosage,although it may act to improve product delivery. Additionalcharacteristics of excipients can be found in the Guidance for IndustryNonclinical Studies for the Safety Evaluation of PharmaceuticalExcipients issued by the US Food and Drug Administration Center for DrugEvaluation and Research (May, 2005), herein incorporated by reference.

The term “flocculant” as used herein refers to a substance that promotesthe clumping of particles.

The term “fragrant” as used herein refers to an aroma compound, alsoknown as odorant, or flavorant, which is a chemical compound that has asmell or odor r when it is sufficiently volatile to be transported tothe olfactory system in the upper part of the nose. Generally moleculesmeeting this specification will have molecular weights of <300 g/mole.Flavors affect both the sense of taste and smell, whereas fragrancesaffect only smell. Generally, flavors tend to be naturally occurring,while fragrances tend to be synthetic. Aroma compounds can be found infood, wine, spices, perfumes, fragrance oils, and essential oils.

The term “hydrogel” as used herein refers to a network of polymer chainsthat are hydrophilic, sometimes found as a colloidal gel in which wateris the dispersion medium. Hydrogels are highly absorbent (they cancontain over 90% water) natural or synthetic polymeric networks.Hydrogels also possess a degree of flexibility very similar to naturaltissue, due to their significant water content.

The term “hydrophilic” as used herein refers to a material or substancehaving an affinity for polar substances, such as water.

The term “impregnate” as used herein in its various grammatical formsrefers to causing to be infused or permeated throughout, or to fillinterstices with a substance.

As used herein the term “inflammation” refers to a physiologic responseto infection and injury in which cells involved in detoxification andrepair are mobilized to the compromised site by inflammatory mediators.The term “acute inflammation” as used herein, refers to inflammation,usually of sudden onset, characterized by the classical signs, withpredominance of the vascular and exudative processes. The term “chronicinflammation” as used herein refers to inflammation of slow progress andmarked chiefly by the formation of new connective tissue; it may be acontinuation of an acute form or a prolonged low-grade form, and usuallycauses permanent tissue damage.

The term “lipid” as used herein refers to a group of naturally occurringmolecules that include fats, waxes, sterols, fat-soluble vitamins (e.g.vitamins A, D, E, and K), mono-di or triglycerides phospholipids, andothers. The main biological functions of lipids include storing energy,signaling, and acting as structural components of cell membranes.Exemplary lipids include natural phospholipids (e.g., egg yolk lecithin(phosphatidyl choline), soybean lecithin, lysolecithin, sphingomyelin,phosphatidic acid, phosphatidyl serine, phosphatidyl glycerol,phosphatidyl inositol, phosphatidyl ethanol amine, diphosphatidylglycerol, cardiolipin and plasmalogen); synthetic lipids (e.g., dicetylphosphate, distearoyl phosphatidyl choline, dioleoylphosphatidyl ethanolamine, dipalmitoyl phosphatidyl choline, diphalmitoyl phosphatidylethanol amine, diphalmitoyl phosphatidyl serine, eleostearoylphosphatidyl choline, eleostearoyl phosphatidyl ethanol amine andeleostearoyl phosphatidyl serine); hydrogenated products that may beobtained from the natural phospholipids or synthetic lipids; derivativesof the natural phospholipids or synthetic lipids; and fatty acidmixtures that may be obtained by hydrolysis of the natural phospholipidsor synthetic lipids.

The term “lipophilic” as used herein refers to preferring or possessingan affinity for a non-polar environment compared to a polar or aqueousenvironment.

The term “liposome” as used herein refers to a man-made sphericalvesicle containing at least one lipid bilayer. The liposome can be usedas a vehicle for administration of components, such as, but not limitedto, pharmaceutical compositions and pharmaceutical formulations, activetherapeutic agents, drugs, enzymes, other proteins and peptides, and DNAand RNA fragments, etc.

The terms “local anesthetic” or “analgesic agents” are usedinterchangeably herein to refer to any drug that provides local numbnessor moderation of painful signals that although still perceived are nolonger painful, or any drug that provides a regional blockage ofnociceptive pathways (afferent and/or efferent). “Local anesthetic” asused herein also encompasses drugs not traditionally associated withlocal anesthetic properties but which have a local anesthetic effect,for example, non-narcotic analgesics, such as, acetylsalicylic acid,ketoprofen, piroxicam, diclofenac, indomethacin, ketorolac, rofecoxib,and celecoxib, and pharmaceutically acceptable salts thereof, ormixtures thereof.

The phrase “localized administration”, as used herein, refers toadministration of a therapeutic agent in a particular location in thebody.

The phrase “localized pharmacologic effect”, as used herein, refers to aconsequence of treatment or a therapeutic effect limited to a certainlocation, i.e. in proximity to a certain location, place, area or site.The phrase “predominantly localized pharmacologic effect”, as usedherein, refers to a therapeutic effect of a drug that is limited to acertain location by at least 1 to 3 orders of magnitude, which isachieved by a localized administration as compared to a systemicadministration.

The term “lubricant” as used herein refers to a substance introduced toreduce friction between surfaces in mutual contact, which ultimatelyreduces the heat generated when the surfaces move. It may also have thefunction of transmitting forces, transporting foreign particles, orheating or cooling the surfaces.

The term “matrix” as used herein refers to a three dimensional networkof fibers that contains voids (or “pores”) where the fibers intersect.The structural parameters of the pores, including the pore size,porosity, pore interconnectivity/tortuosity and surface area, affect howsubstances (e.g., fluid, solutes) move in and out of the matrix.

The term “maximum tolerated dose” as used herein refers to the highestdose of a drug that does not produce unacceptable toxicity.

The terms “minimum effective concentration,” “minimum effective dose,”or “MEC” are used interchangeably to refer to the lowest concentrationof a drug required to produce a desired pharmacological effect in mostpatients.

The terms “neoplasm” or “tumor” as used herein are used interchangeablyto refer to an abnormal mass of tissue that results when cells dividemore than they should or do not die when they should. Neoplasms may bebenign (not cancer) or malignant (cancer). For example, a benignneoplasm (or benign tumor) is a tumor that stops growing by itself, doesnot invade other tissues and does not form metastases

The term “neutral lipid” as used herein refers to a lipid which hasneither a positive or negative charge. Exemplary neutral lipids include,without limitation, cholesterol, cholesterol esters, triglycerides andfatty acids.

The term “non-cellulosic copolymer” as used herein refers to a copolymernot containing or derived from cellulose. The term “cellulose” as usedherein refers to a natural carbohydrate high polymer (polysaccharide)consisting of anhydroglucose units joined by an oxygen linkage to formlong molecular chains that are essentially linear that can be hydrolyzedto glucose.

The term “pain” as used herein refers to a distressing feeling oftencaused by intense or damaging stimuli. As such, the term “pain” ischaracterized by an unpleasant sensory detected and signaled by thenerves and emotional experience associated with actual or potentialtissue damage.

The terms “penetration enhancer” and “permeation enhancer” are usedinterchangeably to refer to natural or synthetic molecules thatfacilitate the transport of co-administered active agents acrossbiological membranes.

The term “pharmaceutical composition” is used herein to refer to acomposition that is employed to prevent, reduce in intensity, cure orotherwise treat a target condition or disease.

The term “pharmaceutically acceptable salt” as used herein refers tothose salts which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and lower animalswithout undue toxicity, irritation, allergic response and the like andare commensurate with a reasonable benefit/risk ratio. When used inmedicine the salts should be pharmaceutically acceptable, butnon-pharmaceutically acceptable salts may conveniently be used toprepare pharmaceutically acceptable salts thereof. Such salts include,but are not limited to, those prepared from the following acids:hydrochloric, hydrobromic, sulphuric, nitric, phosphoric, maleic,acetic, salicylic, p-toluene sulphonic, tartaric, citric, methanesulphonic, formic, malonic, succinic, naphthalene-2-sulphonic, andbenzene sulphonic. Also, such salts may be prepared as alkaline metal oralkaline earth salts, such as sodium, potassium or calcium salts of thecarboxylic acid group. By “pharmaceutically acceptable salt” is meantthose salts which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and lower animalswithout undue toxicity, irritation, allergic response and the like andare commensurate with a reasonable benefit/risk ratio. Pharmaceuticallyacceptable salts are well-known in the art. For example, P. H. Stahl, etal. describe pharmaceutically acceptable salts in detail in “Handbook ofPharmaceutical Salts: Properties, Selection, and Use” (Wiley VCH,Zurich, Switzerland: 2002). The salts may be prepared in situ during thefinal isolation and purification of the compounds described within thedescribed invention or separately by reacting a free base function witha suitable organic acid. Representative acid addition salts include, butare not limited to, acetate, adipate, alginate, citrate, aspartate,benzoate, benzenesulfonate, bisulfate, butyrate, camphorate,camphorsulfonate, digluconate, glycerophosphate, hemisulfate,heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxyethansulfonate (isethionate), lactate, maleate,methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, phosphate, glutamate,bicarbonate, p-toluenesulfonate and undecanoate. Also, the basicnitrogen-containing groups may be quaternized with such agents as loweralkyl halides such as methyl, ethyl, propyl, and butyl chlorides,bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyland diamyl sulfates; long chain halides such as decyl, lauryl, myristyland stearyl chlorides, bromides and iodides; arylalkyl halides likebenzyl and phenethyl bromides and others. Water or oil-soluble ordispersible products are thereby obtained. Examples of acids which maybe employed to form pharmaceutically acceptable acid addition saltsinclude such inorganic acids as hydrochloric acid, hydrobromic acid,sulphuric acid and phosphoric acid and such organic acids as oxalicacid, maleic acid, succinic acid and citric acid. Basic addition saltsmay be prepared in situ during the final isolation and purification ofcompounds described within the invention by reacting a carboxylicacid-containing moiety with a suitable base such as the hydroxide,carbonate or bicarbonate of a pharmaceutically acceptable metal cationor with ammonia or an organic primary, secondary or tertiary amine.Pharmaceutically acceptable salts include, but are not limited to,cations based on alkali metals or alkaline earth metals such as lithium,sodium, potassium, calcium, magnesium and aluminum salts and the likeand nontoxic quaternary ammonia and amine cations including ammonium,tetramethylammonium, tetraethylammonium, methylamine, dimethylamine,trimethylamine, triethylamine, diethylamine, ethylamine and the like.Other representative organic amines useful for the formation of baseaddition salts include ethylenediamine, ethanolamine, diethanolamine,piperidine, piperazine and the like. Pharmaceutically acceptable saltsalso may be obtained using standard procedures well known in the art,for example by reacting a sufficiently basic compound such as an aminewith a suitable acid affording a physiologically acceptable anion.Alkali metal (for example, sodium, potassium or lithium) or alkalineearth metal (for example calcium or magnesium) salts of carboxylic acidsmay also be made.

As used herein the phrase “pharmaceutically acceptable carrier” refersto any substantially non-toxic carrier useable for formulation andadministration of the composition of the described invention in whichthe product of the described invention will remain stable andbioavailable. The pharmaceutically acceptable carrier must be ofsufficiently high purity and of sufficiently low toxicity to render itsuitable for administration to the mammal being treated. It furthershould maintain the stability and bioavailability of an active agent.The pharmaceutically acceptable carrier can be liquid or solid and isselected, with the planned manner of administration in mind, to providefor the desired bulk, consistency, etc., when combined with an activeagent and other components of a given composition.

The term “pharmacologic effect”, as used herein, refers to a result orconsequence of exposure to an active agent.

The term “pharmacokinetics” as used herein describes how the bodyaffects a specific drug after administration through the mechanisms ofabsorption and distribution, as well as the chemical changes of thesubstance in the body (e.g. by metabolic enzymes such as cytochrome P450or glucuronosyltransferase enzymes), and the effects and routes ofexcretion of the metabolites of the drug.

The term “plasticizer” as used herein refers to an additive thatincreases the plasticity or fluidity of a material.

The term, “polyethylene glycol” as used herein is used to refer to acondensation polymer of ethylene glycol with the general formulaHOCH₂(CH₂OCH₂)nCH₂OH or H(OCH₂CH₂)_(n)OH. Average molecular weightsrange from 200 to 6000. Polyethylene glycols can be used as medicamentsfor topical application in the treatment of wounds, for the treatment ofinflammatory skin disease, for the prevention of scar formation and/orfor enhancing the repair of damaged skin or mucosa.

The term “polymer” as used herein refers to a molecule formed by thechemical union of two or more monomer or oligomer units. The chemicalunits are normally linked together by covalent linkages. The two or morecombining units in a polymer can be all the same, in which case thepolymer is referred to as a homopolymer. They can also be different and,thus, the polymer will be a combination of the different units. Suchpolymers are referred to as copolymers. The relationship between thepolymer subunits may be oriented head-to-head or head-to-tail relativeto each subunit. Polymers can be divided into two broad groups:synthetic (non-natural polymers) and natural polymers.

Examples of non-natural polymers include, but are not limited topolyalcohols such as ethylene vinyl alcohol (EVAL), hydroxyethylacrylate, poly(ethylene glycol), poly(vinyl alcohol), poly(hydroxypropylmethacrylamide), poly(propylene glycol); polyamines (such aspolyvinylamine, polyallylamine, tetramethyleneamine,pentamethyleneamine, hexamethyleneamine, bis(2-hydroxyethyl)amine,bis(2-aminoethyl)amine, tris(2-aminoethyl)amine, branched or linearpolyethyleneimine e.g., Lubrasols™—and salts thereof, and derivatives ofpolyethyleneimine such as acylated polyethyleneimine); dendrimers (suchas polyamidoamine (PAMAM) Starburst dendrimers); polyalkylene glycolderivatives (such as amine-substituted polyethylene and polypropyleneglycols); polyacrylates (such as amine-substituted andalcohol-substituted polyacrylates); multi-amino PEG; polymers where thebackbone polymeric structure is substituted with the following pendantnucleophilic or electrophilic groups such as PEG substituted withamines, hydroxylamine, hydrazines, thiols, xanthates, amides,hydrazides, sulfonamides, oximes, malonates, imides, aldehydes,succinimidyl, isocyanates, vinylsulfones, oxiranes, arylhalides,allylhalides, alkyl halides, esters, ethers or anhydrides.

Examples of anionic biopolymers include carboxymethylcellulose and saltsthereof, salts of carboxymethyl and carboxymethylhydroxyethyl starches,and other glucoaminoglycans such as chondroitin sulfate, dermatansulfate, heparin and heparin sulfate and keratin sulfates.

Examples of natural polymers include, without limitation, hyaluronicacid, chondroitin sulfate, alginate, guar gum, fructan, arabinogalactanand any corresponding salt or derivative of thereof.

Hyaluronic acid is a linear polysaccharide (long-chain biologicalpolymer) formed by repeating disaccharide units consisting ofD-glucuronic acid and N-acetyl-D-glucosamine linked by β(1-3) and β(1-4)glycosidic linkages. Hyaluronic acid is distinguished from otherglycosaminoglycans in that is free from covalent links to protein andsulphonic groups. Hyaluronic acid is ubiquitous in animals, with thehighest concentration found in soft connective tissue. The viscoelasticproperties of hyaluronic acid, that is, hard elastic under staticconditions though less viscous under small shear forces, enableshyaluronic acid to basically function as a shock absorber for cells andtissues. Hyaluronic acid also has a relatively large capacity to absorband hold water. These properties of hyaluronic acid are dependent on themolecular weight, the solution concentration, and physiological pH. Atlow concentrations, the individual chains entangle and form a continuousnetwork in solution, which gives the system pronounced viscoelasticityand pseudoplasticity that is unique for a water-soluble polymer at lowconcentration.

As used herein, the term “fructan” refers to all oligosaccharides andpolysaccharides that have a majority of anhydro fructose units andderivatives thereof. The fructan can have a polydisperse chain lengthdistribution and can be straight-chain or branched. The fructans includeprimarily β-2,6 bonds as in levan, or β-2,1 bonds as in a carboxylmodified fructant, e.g., inulin.

Examples of synthetic polymers include, without limitation,polyethylene, polystyrene, polyester, polyvinyl chloride, polyamide,polypropylene, and nylon.

The term “polymersome” as used herein refers to a class of artificialvesicles, tiny hollow spheres that enclose a solution. Polymersomes aremade using amphiphilic synthetic block copolymers to form the vesiclemembrane, and have radii ranging from 50 nm to 5 μm or more. Mostreported polymersomes contain an aqueous solution in their core and areuseful for encapsulating and protecting sensitive molecules, such as butnot limited to pharmaceutical compositions and pharmaceuticalformulations, active therapeutic agents, drugs, enzymes, other proteinsand peptides, and DNA and RNA fragments, etc. The polymersome membraneprovides a physical barrier that isolates the encapsulated material fromexternal materials, such as those found in biological systems.

The term “potency” as used herein refers to efficacy, effectiveness, orstrength of a drug. The potency of a drug is the reciprocal of dose, andhas the units of persons/unit weight of drug or body weight/unit weightof drug. Relative potency compares the relative activity of drugs in aseries relative to some prototypic member of the series. “Efficacy”connotes the property of a drug to achieve the desired response, andmaximum efficacy denotes the maximum achievable effect.

The terms “povidone” “2-pyrrolidinone”, “polyvinylpyrrolidone” and PVPare used interchangeably to refer to a synthetic polymer consisting oflinear 1-vinyl-2-pyrrolidinone groups. PVP is produced commercially as aseries of products having mean molecular weights ranging from about10,000 to about 700,000. The viscosity of solutions containing 10% orless PVP is essentially the same as that of water; solutions moreconcentrated than 10% become more viscous, depending on theconcentration and molecular weight of the polymer used.

The term “preservative” as used herein refers to a substance that isadded to a product to prevent decomposition by microbial growth or byundesirable chemical changes.

The term “reduced” or “to reduce” as used herein refers to a diminution,a decrease, an attenuation or abatement of the degree, intensity,extent, size, amount, density or number.

The term “release” as used herein and its various grammatical forms,refers to dissolution of an active drug component and diffusion of thedissolved or solubilized species. According to some embodiments, thisoccurs by a combination of the following processes: (1) hydration of amatrix, (2) diffusion of a solution into the matrix; (3) dissolution ofthe drug; and (4) diffusion of the dissolved drug out of the matrix.

The term “similar” is used interchangeably with the terms analogous,comparable, or resembling, meaning having traits or characteristics incommon.

The terms “soluble” and “solubility” refer to the property of beingsusceptible to being dissolved in a specified fluid (solvent). The term“insoluble” refers to the property of a material that has minimal orlimited solubility in a specified solvent. In a solution, the moleculesof the solute (or dissolved substance) are uniformly distributed amongthose of the solvent. A “suspension” is a dispersion (mixture) in whicha finely-divided species is combined with another species, with theformer being so finely divided and mixed that it doesn't rapidly settleout. In everyday life, the most common suspensions are those of solidsin liquid.

The terms “solubility enhancer” or “solubilizing agent” are usedinterchangeably to refer to any chemical and/or biological agent able toimprove the solubility of an agent in a solvent. Exemplary solubilityenhancers include povidone, cholesterol, cyclodextrins, and polyethyleneglycols. Exemplary solubility enhancers also include surfactants, whichact as solubilizing agents by forming micelles. The HLB system is usedto describe the characteristics of a surfactant. It is an arbitraryscale to which HLB values are experimentally determined and assigned. Ifthe HLB value is low, the number of hydrophilic groups on the surfactantis small, which means it is more lipophilic (oil soluble) thanhydrophilic (water soluble). Conversely, if the HLB value is high, thereare a large number of hydrophilic groups on the surfactant, which makesit more hydrophilic (water soluble) than oil soluble. An HLB value of 10or higher means that the agent is primarily hydrophilic.

The term “solvent” as used herein refers to a substance capable ofdissolving another substance (termed a “solute”) to form a uniformlydispersed mixture (solution).

The term “stabilizer” as used herein refers to a chemical which tends toinhibit the reaction between two or more other chemicals.

As used herein the term “steroidal anti-inflammatory agent”, refers toany one of numerous compounds containing a 17-carbon 4-ring system andincludes the sterols, various hormones (as anabolic steroids), andglycosides. Representative examples of steroidal anti-inflammatory drugsinclude, without limitation, corticosteroids such as hydrocortisone,hydroxyltriamcinolone, alpha-methyl dexamethasone,dexamethasone-phosphate, beclomethasone dipropionates, clobetasolvalerate, desonide, desoxymethasone, desoxycorticosterone acetate,dexamethasone, dichlorisone, diflucortolone valerate, fluadrenolone,fluclorolone acetonide, flumethasone pivalate, fluosinolone acetonide,fluocinonide, flucortine butylesters, fluocortolone, fluprednidene(fluprednylidene) acetate, flurandrenolone, halcinonide, hydrocortisoneacetate, hydrocortisone butyrate, methylprednisolone, triamcinoloneacetonide, cortisone, cortodoxone, flucetonide, fludrocortisone,difluorosone diacetate, fluradrenolone, fludrocortisone, diflorosonediacetate, fluradrenolone acetonide, medrysone, amcinafel, amcinafide,betamethasone and the balance of its esters, chloroprednisone,chlorprednisone acetate, clocortelone, clescinolone, dichlorisone,diflurprednate, flucloronide, flunisolide, fluoromethalone, fluperolone,fluprednisolone, hydrocortisone valerate, hydrocortisonecyclopentylpropionate, hydrocortamate, meprednisone, paramethasone,prednisolone, prednisone, beclomethasone dipropionate, triamcinolone,and mixtures thereof.

The terms “subject” or “individual” or “patient” are usedinterchangeably to refer to a member of an animal species of mammalianorigin an animal species of mammalian origin, including but not limitedto, mouse, rat, cat, goat, sheep, horse, hamster, ferret, pig, dog,platypus, guinea pig, rabbit and a primate, such as, for example, amonkey, ape, or human.

The phrase “subject in need thereof” as used herein refers to a subjectthat (i) will be administered a topical composition of the describedinvention; (ii) is applying the topical composition of the describedinvention; or (iii) has applied the topical composition of the describedinvention, unless the context and usage of the phrase indicatesotherwise.

When using the terms “substantial”, “substantially”, “essential” or“essentially” herein it is intended that the feature which is describedby these terms is present in an amount or has an impact which providesfor a technical effect with relevance for the exercise of the presentlyclaimed invention. For instance, a “substantial amount” of a substancein a composition is an amount which provides for a technical effectexhibited by the substance to a degree which provides for a technicaleffect in terms of the described invention. Likewise, if a compositionis indicated as comprising “substantially no” with respect to asubstance, this means that the composition is allowed to includeinsignificant amounts of the substance, as long as these amounts do nothave any technical impact on the other ingredients in the compositionand does not in itself “make a difference” or put in other words,“substantially no” and “essentially no” means that e.g. trace amounts oreffects may be present as long as they do not have an overall technicalinfluence.

The term “surfactant” as used herein refers to a compound that lowersthe surface tension (or interfacial tension) between two liquids orbetween a liquid and a solid.

The term “susceptible” as used herein refers to being at risk for.

The term “synergistic effect” as used herein, refers to a combinedeffect of two chemicals, which is greater than the sum of the effect ofeach agent given alone.

The phrase “systemic administration”, as used herein, refers toadministration of a therapeutic agent with a pharmacologic effect on theentire body. Systemic administration includes enteral administration(e.g. oral) through the gastrointestinal tract and parenteraladministration (e.g. intravenous, intramuscular, etc.) outside thegastrointestinal tract.

The terms “therapeutic amount”, “therapeutic effective amount” or an“amount effective” of one or more of the therapeutic agents is an amountthat is sufficient to provide the intended benefit of treatment.Combined with the teachings provided herein, by choosing among thevarious active compounds and weighing factors such as potency, relativebioavailability, patient body weight, severity of adverse side-effectsand preferred mode of administration, an effective prophylactic ortherapeutic treatment regimen may be planned which does not causesubstantial toxicity and yet is effective to treat the particularsubject. Generally, a maximum dose should be used, that is, the highestsafe dose according to some medical judgment. However, dosage levels arebased on a variety of factors, including the type of injury, the age,weight, sex, medical condition of the patient, the severity of thecondition, the route of administration, and the particular therapeuticagent employed. Thus the dosage regimen may vary widely, but can bedetermined routinely by a surgeon using standard methods. “Dose” and“dosage” are used interchangeably herein. Additionally, the terms“therapeutically effective amounts” and “pharmaceutically effectiveamounts” include prophylactic or preventative amounts of thecompositions of the described invention. In prophylactic or preventativeapplications of the described invention, pharmaceutical compositions ormedicaments are administered to a patient susceptible to, or otherwiseat risk of, a disease, disorder or condition in an amount sufficient toeliminate or reduce the risk, lessen the severity, or delay the onset ofthe disease, disorder or condition, including biochemical, histologicand/or behavioral symptoms of the disease, disorder or condition, itscomplications, and intermediate pathological phenotypes presentingduring development of the disease, disorder or condition. Topicaladministration, in contrast to transdermal administration, generallyprovides a local rather than a systemic effect.

The term “therapeutic component” as used herein refers to atherapeutically effective dosage (i.e., dose and frequency ofadministration) that eliminates, reduces, or prevents the progression ofa particular disease manifestation in a percentage of a population. Anexample of a commonly used therapeutic component is the ED50 whichdescribes the dose in a particular dosage that is therapeuticallyeffective for a particular disease manifestation in 50% of a population.

The term “therapeutic effect” as used herein refers to a consequence oftreatment, the results of which are judged to be desirable andbeneficial. A therapeutic effect may include, directly or indirectly,the arrest, reduction, or elimination of a disease manifestation. Atherapeutic effect may also include, directly or indirectly, the arrestreduction or elimination of the progression of a disease manifestation.

The term “thickening agent” refers to a substance that can increase theviscosity of a liquid without substantially changing its otherproperties.

The term “thinning agent” as used herein refers to a substance thatreduces the viscosity of a liquid making it easier to apply.

The term “topical” refers to administration of a pharmaceuticalcomposition at, or immediately beneath, the point of application. Theterms “topically”, “topical administration” and “topically applying” areused interchangeably to refer to delivering a pharmaceutical compositionof the described invention onto one or more surfaces of a tissue orcell, including epithelial surfaces. The composition may be applied bypouring, dropping, or spraying, if a liquid; rubbing on, if an ointment,lotion, cream, gel, or the like; dusting, if a powder; spraying, if aliquid or aerosol composition; or by any other appropriate means.Topical administration generally provides a local rather than a systemiceffect.

The term “treat” or “treating” includes abrogating, substantiallyinhibiting, slowing or reversing the progression of a disease, conditionor disorder, substantially ameliorating clinical or esthetical symptomsof a condition, substantially preventing the appearance of clinical oresthetical symptoms of a disease, condition, or disorder, and protectingfrom harmful or annoying symptoms. The term “treat” or “treating” asused herein further refers to accomplishing one or more of thefollowing: (a) reducing the severity of the disorder; (b) limitingdevelopment of symptoms characteristic of the disorder(s) being treated;(c) limiting worsening of symptoms characteristic of the disorder(s)being treated; (d) limiting recurrence of the disorder(s) in patientsthat have previously had the disorder(s); and (e) limiting recurrence ofsymptoms in patients that were previously symptomatic for thedisorder(s).

As used herein the term “vasoconstrictor” is used to describe an activetherapeutic agent that causes a narrowing of blood vessels resultingfrom contraction of the muscular wall of the vessels, in particular thelarge arteries and small arterioles. The process is the opposite ofvasodilation, the widening of blood vessels.

The term “vitamin” as used herein, refers to any of various organicsubstances essential in minute quantities to the nutrition of mostanimals act especially as coenzymes and precursors of coenzymes in theregulation of metabolic processes.

The term “wetting agent” as used herein refers to a substance thatreduces the surface tension of water in order to allow it to spreaddrops onto a surface, thereby increasing the spreading abilities of aliquid.

The term “wound healing agent” as used herein refers to an agent thatpromotes an intricate process where the skin or other body tissuerepairs itself after injury. In normal skin, the epidermis (surfacelayer) and dermis (deeper layer) form a protective barrier against theexternal environment. As such, the term “wound healing agent” refers toany substance that facilitates the wound healing process.

The term “zwitterion” is a neutral molecule with a positive and anegative electrical charge.

According to one aspect, the described invention provides a topicaldelivery system comprising a pharmaceutical composition formulated forapplication directly to a skin of a subject in need thereof comprising(a) a therapeutic amount of an active therapeutic agent that iseffective to treat symptoms of a disease, disorder or condition; (b) achemical driver comprising an amino benzoate local anesthetic,ethoxydiglycol and methylsulfonylmethane (MSM), wherein the chemicaldrivers are effective to deliver the therapeutic agent to the skin; and(c) a depot component that is effective to keep the active agent locallyin the skin and to reduce distribution of the active to the bloodstream.

Depot Components for Keeping the Pharmaceutical Formulation in the Skinand Facilitating Controlled Release of the Active Agent

According to some embodiments, the composition of the describedinvention contains a depot component that is effective for keeping theactive agent concentrated locally in the skin. According to some suchembodiments, the depot component is effective to facilitate controlledor delayed type release of the active therapeutic agent. According tosome embodiments, the depot component reduces the potential of theactive agent, active metabolite, the chemical drivers, or a combinationthereof to enter the bloodstream. According to some embodiments, thechemical driver component that remains in the skin is effective to allowthe active agent and/or the active metabolite to further diffuse awayfrom the skin, such that the active agent can execute its biologicalfunction at the specific tissue of interest. According to someembodiments, the depot component comprises a liposome. According to someembodiments, the depot component comprises a polymer. According to someembodiments, the depot component comprises a complex of a liposome and apolymer or a polymersome. Other examples of depot components include,without limitation, micelles, reverse micelles, emulsions,microemulsions, etc.

Liposomes are generally known as sub-micron spherical vesicles comprisedof phospholipids and cholesterol that form a hydrophobic bilayersurrounding an aqueous core. These structures have been used with a widevariety of therapeutic agents and allow for a drug to be entrappedwithin the liposome based in part upon its own hydrophobic (e.g. bilayerentrapment) or hydrophilic properties (e.g. entrapment in the aqueouscompartment). Liposomes are generally used for controlled release andfor drug targeting of lipid-capsulated compounds (Betageri et al,Liposome Drug Delivery Systems, Technomic Publishing Co., Inc.,Lancaster, Pa., 1993).

Typically, encapsulating a drug, an active therapeutic agent or apharmaceutical composition in a liposome can alter the pattern ofbio-distribution and the pharmacokinetics for the drugs. In certaincases, liposomal encapsulation has been found to lower drug toxicity.For example, long circulating liposomal formulations can avoid uptake byorgans of the mononuclear phagocyte system, primarily in the liver andspleen. According to some embodiments, such long-circulating liposomesmay include a surface coat of flexible water soluble polymer chains thatact to prevent interaction between the liposome and plasma componentsthat play a role in liposome uptake. According to some embodiments, suchliposomes can be made of saturated, long-chain phospholipids andcholesterol, without this coating.

Exemplary liposomes may comprise a lipid layer comprising liposomeforming lipids. The lipid may include at least one phosphatidyl cholinewhich provides the primary packing/entrapment/structural element of theliposome. The phosphatidyl choline comprises mainly C₁₆ or longerfatty-acid chains. Chain length provides for both liposomal structure,integrity, and stability. Optionally, one of the fatty-acid chains mayhave at least one double bond. As used herein, the term “phosphatidylcholine” includes, without limitation, soy PC, egg PC dielaidoylphosphatidyl choline (DEPC), lecithin, dioleoyl phosphatidyl choline(DOPC), distearoyl phosphatidyl choline (DSPC), hydrogenated soybeanphosphatidyl choline (HSPC), dipalmitoyl phosphatidyl choline (DPPC),1-palmitoyl-2-oleo phosphatidyl choline (POPC), dibehenoyl phosphatidylcholine 30 (DBPC), and dimyristoyl phosphatidyl choline (DMPC).

As used herein, the term “Soy-PC” refers to phosphatidyl cholinecompositions including a variety of mono-, di-, tri-unsaturated, andsaturated fatty acids. Soy-PC may include palmitic acid present in anamount of about 12% to about 33% (i.e., about 12%, about 13%, about 14%,about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%,about 28%, about 29%, about 30%, about 31%, about 32%, or about 33%) byweight; stearic acid present in an amount of about 3% to about 8% (i.e.,about 3%, about 4%, about 5%, about 6%, about 7%, or about 8%) byweight; oleic acid present in an amount of about 4% to about 22% (i.e.,about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%,about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about17%, about 18%, about 19%, about 20%, about 21%, or about 22%), byweight; linoleic acid present in an amount of about 60% to about 66%(i.e., about 60%, about 61%, about 62%, about 63%, about 64%, about 65%,or about 66%) by weight; and linolenic acid present in an amount ofabout 5% to about 8% (i.e., about 5%, about 6%, about 7%, or about 8%)by weight.

As used herein, the term “Egg-PC” refers to a phosphatidyl cholinecomposition including, but not limited to, a variety of saturated andunsaturated fatty acids. For example, Egg-PC may comprise palmitic acidpresent in an amount of 10 about 34% (i.e., about 10%, about 11%, about12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%,about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%,about 32%, about 33% or 3 about 4%) by weight; stearic acid present inan amount of about 10% by weight; oleic acid present in an amount ofabout 31% by weight; and linoleic acid present in an amount of about 18%by weight.

According to some embodiments, the liposome comprises cholesterol. Theratio of phosphatidyl choline to cholesterol may be, for example, fromabout 0.5:1 to about 4:1 by mole ratio. According to some embodiments,the ratio of phosphatidyl choline to cholesterol may be from about 1:1to about 2:1 by mole ratio, e.g., about 1.1; about 1.1:1; about 1.2:1:about 1.3:1; about 1.4:1; about 1.5:1; about 1.6:1; about 1.7:1; about1.8:1; about 1.9:1, or about 2:1. According to some embodiments, theratio of phosphatidyl choline to cholesterol may be about 2:1 by moleratio.

As used herein the term “total lipid” includes phosphatidyl cholines andany anionic phospholipid present in the liposome membrane.

The liposome may also comprise physiologically acceptable salts tomaintain proper isotonicity. Any pharmaceutically acceptable salt thatachieves isotonicity is acceptable, including, without limitation, forexample, e.g. NaCl.

The liposomes of the described invention may comprise a lipid layer ofphospholipids and cholesterol. According to some embodiments, the ratioof phospholipid to cholesterol is sufficient to form a liposome thatwill not dissolve or disintegrate once administered to the animal. Thephospholipids and cholesterol may be dissolved in suitable solvent orsolvent mixtures. After a suitable amount of time, the solvent isremoved via vacuum drying and/or spray drying. The resulting solidmaterial can be stored or used immediately. Subsequently, the resultingsolid material is hydrated in an aqueous solution containing anappropriate concentration of the therapeutic agent at an appropriatetemperature, resulting in multilamellar vesicles (MLV). The solutionscontaining MLV can be size-reduced via homogenization to form SmallUnilameller Vesicles (SUVs) with the drug passively entrapped within theformed SUVs. The resulting liposome solution can be separated fromunencapsulated therapeutic agent, for example by chromatography orfiltration, and then filtered for use.

According to some embodiments, an anionic liposome may also be used.According to some embodiments, an anionic liposome provides a Coulombiccharacter to the liposomes. According to some embodiments, anioniclipids can help stabilize the system upon storage, can prevent fusion oraggregation or flocculation, and can facilitate or enable freeze drying.Exemplary anionic lipids include, without limitation, phospholipids inthe phosphatidic acid, phosphatidylglycerol, and phosphatidylserineclasses (PA, PG, and PS). Further examples include C₁₆ or largerfatty-acid chains. Further exemplary anionic phospholipid include,without limitation, Egg-PG (Egg Phosphatidyglycerol), Soy-PG(Soy-Phosphatidylglycerol), DSPG 20 (Distearoyl Phosphatidyglycerol),DPPG (Dipalmitoyl Phosphatidyglycerol), DEPG (DielaidoylPhosphatidyglycerol), DOPG (Dioleoyl Phosphatidyglycerol), DSPA(Distearoyl Phosphatidic Acid), DPPA (Dipalmitoyl Phosphatidic Acid),DEPA (Dielaidoy Phosphatidic Acid), DOPA (Dioleoyl Phosphatidic Acid),DSPS (Distearoyl Phosphatidylserine), DPPS (DipalmitoylPhosphatidylserine), 25 DEPS (Dielaidoy Phosphatidylserine), and DOPS(Dioleoyl Phosphatidylserine), or any mixtures thereof.

According to some embodiments, a cationic liposome may be used.Exemplary cationic lipids include, without limitation, stearylamine(SA), lauryltrimethylammonium bromide; cetyltrimethylammonium bromide,myristyl trimethylammonium bromide, dimethyldioctadecylammonium bromide(DDAB), 3β-[N—(N′,N′-dimethylaminoethane)-carbamoyl]cholesterol(DC-Cholesterol), 1,2-ditetradecanoyl-3-trimethylammonium-propane(DMTAP), 1,2-dioctadecanoyl-3-trimethylammonium-propane (DOTAP) andDOTAP derivatives such as1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane and1,2-dihexadecanoyl-3-trimethylammonium-propane,1,2-di-(9Z-octadecenoyl)-3-dimethylammonium-propane (DODAP) and DODAPderivatives such as 1,2-ditetradecanoyl-3-dimethylammonium-propane,1,2-dihexadecanoyl-3-dimethylammonium-propane, and1,2-dioctadecanoyl-3-dimethylammonium-propane,1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA),1,2-dioleoyl-c-(4′-trimethylammonium)-butanoyl-sn-glycerol (DOTB),dioctadecylamide-glycylspermine, SAINT-2, polycationic lipid2,3-dioleyloxy-N-[2(spermine-carboxamido)ethyl]-N,N-dimethyl-1-propanaminiumtrifluoroacetate(DOSPA), and GL67™. The cationic lipids may also constitute derivativesof the foregoing. Additional examples of cationic lipids and lipidcomponents may be found in or made according to U.S. Pat. No. 4,804,539issued to Guo et al, which is incorporated herein by reference.According to some embodiments, the liposomes may contain about 10-40(i.e., about 10, about 11, about 12, about 13, about 14, about 15, about16, about 17, about 18, about 19, about 20, about 21, about 22, about23, about 24, about 25, about 26, about 27, about 28, about 29, about30, about 31, about 32, about 33, about 34, about 35, about 36, about37, about 38, about 39, or about 40) mole percent of anamine-derivatized lipid component in which a charged amine group isspaced from a lipid polar head region by a carbon-containing spacer armat least 3 atoms in length. According to some embodiments, the liposomeshave a close packed lipid structure produced by inclusion of between20-50 (i.e., about 20, about 21, about 22, about 23, about 24, about 25,about 26, about 27, about 28, about 29, about 30, about 31, about 32,about 33, about 34, about 35, about 36, about 37, about 38, about 39,about 40, about 41, about 42, about 43, about 44, about 45, about 46,about 47, about 48, about 49, or about 50) mole percent of cholesterolor an amine-derivatized cholesterol, and/or phospholipids withpredominantly saturated acyl chain moieties. According to someembodiments, the liposomes may be suspended in an aqueous mediumcontaining a high-viscosity polymer, formulated in paste form, orembedded in a polymer matrix, to further enhance liposome retention.

Polymers can also be used for controlled or delayed type releaseprocedures (Langer, Accounts Chem. Res. 26:537, 1993). For example, theblock copolymer, polaxamer 407 exists as a viscous yet mobile liquid atlow temperatures but forms a semisolid gel at body temperature. It hasbeen shown to be an effective vehicle for formulation and sustaineddelivery of recombinant interleukin-2 and urease (Johnston et al, Pharm.Res. 9:425, 1992; Pec, J. Parent. Set Tech. 44(2):58, 1990).Alternatively, hydroxyapatite has been used as a microcarrier forcontrolled release of proteins (Ijntema et al, Int. J. Pharm. 112:215,1994). Other illustrative and exemplary polymers utilized either alone,in combination, in association with a liposome, or as a polymersome, mayinclude for example, Poly(ethylene glycol) (PEG/PEO),Poly(2-methyloxazoline), Polydimethylsiloxane (PDMS), Poly(caprolactone(PCL), Poly(lactide) (PLA), Poly(methyl methacrylate) (PMMA), povidone,cellulose acetate phthalate (CAP), hydroxypropyl methylcellulosephthalate (HPMCP), polyvinyl acetate phthalate (PVAP), hydroxypropylmethylcellulose acetate succinate (HPMCAS), cellulose acetatetrimellitate, hydroxypropyl methylcellulose succinate, cellulose acetatesuccinate, cellulose acetate hexahydrophthalate, cellulose propionatephthalate, copolymer of methylmethacrylic acid and methyl methacrylate,copolymer of methyl acrylate, methylmethacrylate and methacrylic acid,copolymer of methylvinyl ether and maleic anhydride (Gantrez ES series),ethyl methyacrylate-methylmethacrylate-chlorotrimethylammonium ethylacrylate copolymer, natural resins such as zein, shellac and copalcollophorium, and several commercially available enteric dispersionsystems (e.g., EUDRAGIT® L30D55, EUDRAGIT® FS30D, EUDRAGIT® L100,KOLLICOAT® EMM30D, ESTACRYL® 30D, COATERIC®, and AQUATERIC®). Theforegoing is not a comprehensive and exhaustive list, and there areother polymeric materials that would meet the objectives of thedescribed invention of providing for a controlled or delayed typerelease profile of the active therapeutic agent from the skin.

Delivery System Containing Pharmaceutical Compositions

According to some embodiments, the therapeutic agent and/or activemetabolite remains in the skin and does not enter the bloodstream.

According to some embodiments, the chemical driversmethylsulfonylmethane (MSM), an amino benzoate local anesthetic, andethoxydiglycol work together cooperatively and synergistically todeliver the active therapeutic agent.

MSM (formula (CH₃)2SO₂), also known as DMSO2, methyl sulfone, anddimethyl sulfone. CAS Registry Number 67-71-0) is an organosulfurcompound, and as shown in Formula (I), is a polar molecule having twooxygen atoms that can readily interact with positively charged atoms ormolecules.

According to some embodiments, MSM can be administered in a maximumdaily dose of up to 6 g/day; according to some embodiments MSM ispresent as from 1-10% w/w of the pharmaceutical composition, i.e., 1%,2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% w/w of the pharmaceuticalcomposition.

Research in animal models indicates MSM has a very low toxicity whenadministered topically (see Liu, P. et al., “Metal Chelator combinedwith permeability enhancer ameliorates oxidative stress-associatedneurodegeneration in rat eyes with elevated intraocular pressure,” FreeRadic. Biol. Med. 69: 289-99 (2014)).

Zhang and coworkers determined that MSM functions as a permeabilityenhancer and an excipient to facilitate transport of the chelator EDTA(Mw=292.24 g/mol) across biologic membranes, and to make possiblelocalized and regional chelation. Topical application of MSM with C¹⁴EDTA onto the rat cornea led to an uptake of the C¹⁴ EDTA in all testedocular tissues. Without MSM, EDTA did not penetrate the eye.Additionally, Zhang and co-workers suggested that MSM could also be anadjuvant for delivering ciprofloxacin and other chemical compounds tospecific, local tissue sites (See “Assessment of methylsulfonylmethaneas a permeability enhancer for regional EDTA chelation therapy”; DrugDelivery; Vol. 16; Pages 243-248, 2009), the disclosure of which isincorporated by reference.

Ethoxydiglycol (also known as diethylene glycol monoethyl ether havingformula CH₃CH₂OCH₂CH₂OCH₂CH₂OH) 2-(2-ethoxyethyoxy)ethanol, CAS RegistryNumber 111-90-0) is a low molecular weight cosmetic grade syntheticsolvent and viscosity decreasing agent used in cosmetics and personalcare products to ensure even distribution of the ingredients throughouta product. Glycols are a class of alcohols that contain two hydroxylgroups, and are also called a diols. According to some embodiments,ethoxydiglycol is present in a range of 0.10-5% w/w of thepharmaceutical composition, i.e., 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%,0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%,1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%,3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%,4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9% or 5% w/w of the pharmaceuticalcomposition.

According to some embodiments, the molecular weight of the therapeuticagent of the described invention is less than 500 Da.

The cumulative effect of these three components together is more thanadditive. As such, lower amounts of each component can be used thanwould normally be used alone to deliver an active therapeutic agent.According to some embodiments, the chemical drivers enhance delivery ofactive therapeutic agents having a molecular weight of less than 500 Da.According to some embodiments, the chemical drivers may also be able toenhance delivery of active therapeutic agents having a molecular weighthigher than 500 Da.

According to some embodiments, the synergistic effect of the MSM, aminobenzoate local anesthetic, and ethoxydiglycol, is effective to provideincreased speed to anesthesia, and a reduction of the amino benzoatelocal anesthetic and the therapeutic agent concentration because ofimproved penetration of the stratum corneum resulting in effectiveanalgesia.

According to some embodiments, the amino benzoate local anestheticblocks nerve signals where applied. According to some embodiments, thechemical drivers are effective to increase percutaneous perfusionwherein heat, pH and the polarity of the chemical drivers are factorsthat affect percutaneous perfusion.

Exemplary amino benzoate local anesthetics include, without limitation,lidocaine (1-10%, i.e., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%) w/wof the composition), benzocaine (5-20% (i.e., 5%, 6%, 7%, 8%, 9%, 10%,11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%) w/w of thecomposition), and tetracaine (2% w/w of the composition). Alternatively,any other suitable local anesthetic can be used including, withoutlimitation, ambucaine, amolanone, amylcaine, benoxinate, benzocaine,betoxycaine, biphenamine, bupivacaine, butacaine, butamben,butanilicaine, butethamine, butoxycaine, carticaine, chloroprocaine,cocaethylene, cocaine, cyclomethycaine, dibucaine, dimethisoquin,dimethocaine, diperodon, dyclonine, ecogonidine, ecogonine, euprocin,fenalcomine, formocaine, hexylcaine, hydroxyteteracaine, isobutylp-aminobenzoate, leucinocaine, levoxadrol, lidocaine, mepivacaine,meprylcaine, metabutoxycaine, methyl chloride, myrtecaine, naepaine,octacaine, orthocaine, oxethazaine, parenthoxycaine, phenacaine, phenol,piperocaine, piridocaine, polidocanol, pramoxine, prilocaine, procaine,propanocaine, proparacaine, propipocaine, propoxycaine, pseudococaine,pyrrocaine, ropivacaine, salicyl alcohol, tetracaine, tolycaine,trimecaine, zolamine, or a pharmaceutically acceptable salt thereof, ora mixture thereof. Amide type local anesthetics are characterized by anamide functionality, while ester type local anesthetics contain an esterfunctionality. Exemplary amide type local anesthetics includebupivacaine, prilocaine, mepivacaine, etidocaine, ropivacaine,dibucaine, and mixtures thereof. Exemplary ester type local anestheticsinclude procaine, chloroprocaine, their pharmaceutically acceptablesalt, or a mixture thereof.

According to some embodiments, the amino benzoate local anesthetic islidocaine (or lidocaine HCl), also known as2-(diethylamino)-/V-(2,6-dimethylphenyl)acetamide shown in Formula (II).

Lidocaine can be administered in amounts of 0.5 to 4.5 mg/kg/dose (i.e.,0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 4.5 mg/kg/dose). Thelidocaine can be in the form of viscous lidocaine 2% w/w generally usedto treat sore throat, teething, mouth or esophageal sores, or swellinginside the mouth. Viscous lidocaine can also be used to prevent gaggingduring dental procedures. Lidocaine spray 4% w/w can be used under“crash” circumstances, where speed is of the essence. Lidocaine spray isgenerally used when a breathing tube is inserted down the larynx duringintubation to numb the gag reflex. Combined with the other components ofthe topical composition for fast anesthesia, time to perform intubationcan be decreased where even a few seconds reduced can save a life.Lidocaine spray can also be used during childbirth. Lidocaine spray iscommercially available as a 10% w/w solution, and the maximum dose perday is 30 mg within 30 minutes.

Other amino benzoate local anesthetics with similar dosing to lidocaineinclude tetracaine (2-(dimethylamino)ethyl 4-(butylamino)benzoate),shown in Formula (III), and benzocaine (ethyl 4-aminobenzoate), shown inFormula (IV).

Exemplary active therapeutic agents may include without limitation,analgesic agents, wound healing agents, anti-inflammatory agents(steroidal and non-steroidal); anti-oxidant agents; antihistamines oranti-neoplastics either singly or as a combination thereof.

According to some embodiments, the active agent of the topicalcomposition of the described invention can be an analgesic agent.Exemplary analgesics may include the following molecules but not limitedto non-steroidal anti-inflammatory drugs (NSAIDS), e.g., paracetamol(acetaminophen), ibuprofen, naproxen, and, COX-2 inhibitors, opioids,flupirtine, and specific agents including, but not limited to tricyclicantidepressants, such as amitriptyline, nefopam, and anticonvulsants,including carbamazepine, gabapentin, and pregabalin.

According to some embodiments, the active agent of the topicalcomposition of the described invention is an antineoplastic agent.Exemplary anti-neoplastics may include, without limitation5-fluorouracil, temozolomide, busulfan, ifosamide, melphalan,carmustine, lomustine, mesna, capecitabine, gemcitabine, floxuridine,decitabine, mercaptopurine, pemetrexed disodium, methotrexate,vincristine, vinblastine, vinorelbine tartrate, paclitaxel, docetaxel,ixabepilone, daunorubicin, epirubicin, doxorubicin, idarubicin,amrubicin, pirarubicin, mitoxantrone, etoposide, etoposide phosphate,teniposide, mitomycin C, actinomycin D, colchicine, topotecan,irinotecan, gemcitabine cyclosporin, verapamil, valspodor, probenecid,biricodar, terfenadine, quinidine, and pervilleine A.

According to some embodiments, the active agent of the topicalcomposition of the described invention comprises an anti-inflammatoryagent. Non-limiting examples of non-steroidal anti-inflammatory agentsinclude, ibuprofen (Advil®), naproxen sodium (Aleve®), and acetaminophen(Tylenol®), oxicams, such as piroxicam, isoxicam, tenoxicam, sudoxicam,and CP-14,304; disalcid, benorylate, trilisate, safapryn, solprin,diflunisal, and fendosal; acetic acid derivatives, such as diclofenac,fenclofenac, indomethacin, sulindac, tolmetin, isoxepac, furofenac,tiopinac, zidometacin, acematacin, fentiazac, zomepirac, clindanac,oxepinac, felbinac, and ketorolac; fenamates, such as mefenamic,meclofenamic, flufenamic, niflumic, and tolfenamic acids; propionic acidderivatives, such as benoxaprofen, flurbiprofen, ketoprofen, fenoprofen,fenbufen, indopropfen, pirprofen, carprofen, oxaprozin, pranoprofen,miroprofen, tioxaprofen, suprofen, alminoprofen, and tiaprofenic;pyrazoles, such as phenylbutazone, oxyphenbutazone, feprazone,azapropazone, and trimethazone. Mixtures of these non-steroidalanti-inflammatory agents also may be employed, as well as thedermatologically acceptable salts and esters of these agents. Forexample, etofenamate, a flufenamic acid derivative, can be used fortopical application.

Non-limiting examples of steroidal anti-inflammatory agents includecorticosteroids such as hydrocortisone, hydroxyltriamcinolone,alpha-methyl dexamethasone, dexamethasone-phosphate, beclomethasonedipropionates, clobetasol valerate, desonide, desoxymethasone,desoxycorticosterone acetate, dexamethasone, dichlorisone,diflucortolone valerate, fluadrenolone, fluclorolone acetonide,flumethasone pivalate, fluosinolone acetonide, fluocinonide, flucortinebutylesters, fluocortolone, fluprednidene (fluprednylidene) acetate,flurandrenolone, halcinonide, hydrocortisone acetate, hydrocortisonebutyrate, methylprednisolone, triamcinolone acetonide, cortisone,cortodoxone, flucetonide, fludrocortisone, difluorosone diacetate,fluradrenolone, fludrocortisone, diflorosone diacetate, fluradrenoloneacetonide, medrysone, amcinafel, amcinafide, betamethasone and thebalance of its esters, chloroprednisone, chlorprednisone acetate,clocortelone, clescinolone, dichlorisone, diflurprednate, flucloronide,flunisolide, fluoromethalone, fluperolone, fluprednisolone,hydrocortisone valerate, hydrocortisone cyclopentylpropionate,hydrocortamate, meprednisone, paramethasone, prednisolone, prednisone,beclomethasone dipropionate, triamcinolone, and mixtures thereof.

According to some embodiments, the active agent of the topicalcomposition of the described invention comprises an anti-oxidant agent.Exemplary anti-oxidants may include ascorbic acid (vitamin C) and itssalts, ascorbyl esters of fatty acids, ascorbic acid derivatives (e.g.,magnesium ascorbyl phosphate, sodium ascorbyl phosphate, ascorbylsorbate), tocopherol (vitamin E), tocopherol sorbate, tocopherolacetate, other esters of tocopherol, butylated hydroxy benzoic acids andtheir salts, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid(commercially available under the tradename TroloxR), gallic acid andits alkyl esters, especially propyl gallate, uric acid and its salts andalkyl esters, sorbic acid and its salts, lipoic acid, amines (e.g.,N,N-diethylhydroxylamine, amino-guanidine), sulfhydryl compounds (e.g.,glutathione), dihydroxy fumaric acid and its salts, glycine pidolate,arginine pilolate, nordihydroguaiaretic acid, bioflavonoids, curcumin,lysine, methionine, proline, superoxide dismutase, silymarin, teaextracts, grape skin/seed extracts, melanin, and rosemary extracts.

According to some embodiments, the antioxidant may be alpha tocopherol(Vitamin-E), ascorbic acid, ascorbic acid esters, glutathione, lipoicacid, uric acid, carotenes, propyl gallate, sodium bisulfite, sodiumsulfite, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA),or cysteine.

According to some embodiments, the active agent of the topicalcomposition of the described invention comprises an antihistamine.Non-limiting examples of antihistamines include, without limitation,chlorpheniramine, brompheniramine, dexchlorpheniramine, tripolidine,clemastine, diphenhydramine, promethazine, piperazines, piperidines,astemizole, loratadine and terfenadine.

According to some embodiments, the topical composition of the describedinvention further contains a topical vasoconstrictor as an additionalactive agent. Non-limiting examples of topical vasoconstrictors include,for example, oxymetazoline, isoproterenol, phenylephrine,norepinephrine, ephedrine, epinephrine, dobutamine, droxidopa,vasopressin, pseudoephedrine. According to some embodiments, thevasoconstrictor is not a substance that causes a dermatitis or otherirritation, e.g., epinephrine, synephrine, or ephedrine.

According to some embodiments, the topical composition is characterizedby controlled release or delayed release of locally sustained levels ofa minimum effective concentration (MEC) of the active agent.

The intensity of effect of a drug (y-axis) can be plotted as a functionof the dose of drug administered (X-axis). Goodman & Gilman's ThePharmacological Basis of Therapeutics, Ed. Joel G. Hardman, Lee E.Limbird, Eds., 10^(th) Ed., McGraw Hill, New York (2001), p. 25, 50).These plots are referred to as dose-effect curves. Such a curve can beresolved into simpler curves for each of its components. Theseconcentration-effect relationships can be viewed as having fourcharacteristic variables: potency, slope, maximal efficacy, andindividual variation.

The location of the dose-effect curve along the concentration axis is anexpression of the potency of a drug. Id. If the active therapeutic agentis to be administered by transdermal absorption, a highly potent activetherapeutic agent is required, since the capacity of the skin to absorbactive therapeutic agents is limited.

The slope of the dose-effect curve reflects the mechanism of action of adrug. The steepness of the curve dictates the range of doses useful forachieving a clinical effect.

Maximal or clinical efficacy refers to the maximal effect that can beproduced by a drug. Maximal efficacy is determined principally by theproperties of the drug and its receptor-effector system and is reflectedin the plateau of the curve. In clinical use, a drug's dosage may belimited by undesired effects.

Biological variability may exist. An effect of varying intensity mayoccur in different individuals or subjects at a specified concentrationor a drug. It follows that a range of concentrations may be required toproduce an effect of specified intensity in all subjects.

Lastly, different individuals may vary in the magnitude of theirresponse to the same concentration of a drug when the appropriatecorrection has been made for differences in potency, maximal efficacyand slope.

The duration of a drug's action is determined by the time period overwhich concentrations exceed the MEC. Following administration of a doseof drug, its effects usually show a characteristic temporal pattern. Aplot of drug effect vs. time illustrates the temporal characteristics ofdrug effect and its relationship to the therapeutic window. A lag periodis present before the drug concentration exceeds the minimum effectiveconcentration (MEC) for the desired effect. Following onset of theresponse, the intensity of the effect increases as the drug continues tobe absorbed and distributed. This reaches a peak, after which drugelimination results in a decline in the effect's intensity thatdisappears when the drug concentration falls back below the MEC. Thetherapeutic window reflects a concentration range that provides efficacywithout unacceptable toxicity. Accordingly another dose of drug shouldbe given to maintain concentrations within the therapeutic window.

According to some embodiments, the potency of the active therapeuticagent in the claimed pharmaceutical composition is maintained within arange of from 3 to 5% w/w of the composition i.e., at least 2% w/w ofthe composition when the local anesthetic is lidocaine; from 10 to 20%(10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%) w/w of thecomposition i.e., at least 5% w/w of the composition when the localanesthetic is benzocaine and from 1 to 2% (i.e., 1.0%, 1.1%, 1.2%, 1.3%,1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%) w/w of the composition i.e.,at least 1%) w/w of the composition when the local anesthetic istetracaine.

According to some embodiments, the concentration of the activetherapeutic agent is at least 1% w/w of the composition, at least 2% w/wof the composition, at least 3% w/w of the composition, at least 4% w/wof the composition, at least 5% w/w of the composition, at least 6% w/wof the composition, at least 7% w/w of the composition, at least 8% w/wof the composition, at least 9% w/w of the composition, at least 10% w/wof the composition; at least 11% w/w of the composition; at least 12%w/w of the composition; at least 13% w/w of the composition; at least14% w/w of the composition; at least 15% w/w of the composition; atleast 16% w/w of the composition; at least 17% w/w of the composition;at least 18% w/w of the composition; at least 19% w/w of thecomposition; at least 20% w/w of the composition, at least 30% w/w ofthe composition, at least 40% w/w of the composition, at least 50% w/wof the composition, or at least 60% w/w of the composition. According tosome embodiments, the concentration of the active agent is from about 1%to about 10% w/w of the composition, i.e., at least 1%, at least 2%, atleast 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least8%, at least 9%, or 10% w/w of the composition when the local anestheticis lidocaine. According to some embodiments, the concentration of theactive agent is from about 5% to about 20% w/w of the composition, i.e.,at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, atleast 10%, at least 11%), at least 12%, at least 13%, at least 14%, atleast 15%, at least 16%, at least 17%, at least 18%, at least 19% or 20%w/w of the composition when the local anesthetic is benzocaine.According to some embodiments, the concentration of the active agent isfrom about 1% to about 2% w/w of the composition, i.e. at least 1%, or2% w/w of the composition when the local anesthetic is tetracaine.

According to some embodiments, the content of the active agent retainedon skin and its permeation/flux into the skin can be measured as afunction of time. According to some embodiments, flux is determinedusing one of many available artificial membranes attached to a Franzdiffusion cell. According to some embodiments, permeation and retentionare determined using human cadaver skin attached to a Franz diffusioncell. According to some embodiments, the retained concentration iscorrelated to the minimum effective concentration.

According to some embodiments, the pharmaceutical composition can beapplied directly to the skin.

The pharmaceutical composition may further include auxiliary agents,e.g., lubricants, preservatives, stabilizers, wetting agents,emulsifiers, salts for influencing osmotic pressure, buffers, colorants,flavorants and/or fragrances and the like which are compatible with theactive compounds, carriers, excipients, flocculants, penetrationenhancers, plasticizers, pH balancers, moisturizers, emollients,surfactants and emulsifiers, bactericides, thickening agents, softeningagents, etc.

The composition can also include agents that assist in maintaining themolecular structure integrity of the therapeutic or help deliver thetherapeutic agent through the skin, such as but not limited to solventsthat break down lipophilic therapeutics or adjust ionic charge foreasier delivery into skin, detergents such as but not limited to anionicdetergents (e.g., alkylbenzenesulfonates), cationic detergents,non-ionic detergents (e.g., ethoxylates, PEGylates), or zwitterionicdetergents (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate)),cyclodextrins that readily complex with lipophilic therapeutics likesteroids, including cc-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin,other complexing agents (i.e. chelating agents with two or more separatecoordinate bonds between a multiple bonded ligand and a central atom(metal), such as, but not limited to, glutamic acid, histidine, malate,phytochelatin, hemoglobin, chlorophyll, ethylenediaminetetraacetic acid(EDTA), amino acid chelates, and dimercaprol), and other amphipathicchemicals.

Exemplary plasticizers include, without limitation, phthalic anhydrideesters, esters of adipic acid, epoxidized esters, trimellitic esters,triacetin, N-methyl-2-pyrrolidone, glycerol formaldehyde, triethylcitrate (TEC), acetyltributylcitrate, ethanol, and polyethylene glycol.

Non-limiting examples of penetration enhancers include propylene glycol(PG), dimethylsulfoxide (DMSO), dimethyl formamide (DMF), allantoin,urazole, N,N-dimethylacetamide (DMA), decylmethylsulfoxide (C10 MSO),polyethylene glycol monolaurate (PEGML), propylene glycol monolaurate(PGML), glycerol monolaurate (GML), lecithin, the 1-substitutedazacycloheptan-2-ones, e.g., 1-n-dodecylcyclazacycloheptan-2-one(available under the trademark Azone® from Whitby Research Incorporated,Richmond, Va.), alcohols, and the like. The penetration enhancer mayalso be a vegetable oil, for example, safflower oil, cottonseed oil andcorn oil. Additional penetration enhancers may generally be found inRemington's Pharmaceutical Sciences, 18th or 19th editions, published bythe Mack Publishing Company of Easton, Pa. which is incorporated hereinby reference.

Exemplary anti-oxidants may include the following, but not limited to,ascorbic acid and glutathione (GSH) etc. According to some embodiments,the antioxidant agent is present at a concentration from 10%-20% (i.e.,10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%) w/w of thecomposition for ascorbic acid and from 2%-5% (i.e., 2%, 2.1%, 2.2%,2.3%, 2.4%, 2.5%, 2.6%, 2.7% 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%,3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%,4.7%, 4.8%, 4.9%, or 5%) for glutathione.

Surfactants are organic compounds that are amphiphatic, containing bothhydrophobic groups and hydrophilic groups. Surfactants include, but arenot limited to anionic surfactants, cationic surfactants and non-ionicsurfactants.

Anionic surfactants include fatty acid soaps (including sodium oleate,sodium palmitate, sodium myristate, sodium sterate, potassium oleate andtriethanolamine oleate); alkyl sulfates (including sodium dodecylsulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate andsodium alkyl sulfate); alkyl lactylates (including calciumstearoxyl-2-lactylate), alkyl lactates (includingsodium-O-stearyllactate and sodium stearoyllactylate) alkylbenzenesulfonates (including calcium dodecyl benzene sulfonate); alkylsulfonates (including alkyl aryl sulfonate); alkyl phosphates; alkyloleates; alkyl stearates (including self-emulsifying glycerolmonostearate); alkyl esters (including dioctyl ester of sodiumsulphosuccininc acid (AOT, Aerosol OT); acyl sulfates; or acylsulfosuccinates.

Cationic surfactants include alkyl primary, secondary, tertiary, orquaternary amines; high-molecular-weight amine and fatty amine blends;polyoxyethylene fatty amines (including tallow amine); alkyl sulfates(including N-cetyl-N-ethyl morpholinium ethyl sulfate (35%)); alkylpyridinium and quaternary ammonium salts.

Non-ionic surfactants include alcohol ethoxylate, alkylphenolethoxylate, fatty acids (such as oleic acid), lanolin alcohols (such aspolyoxyethylene (5) lanolin alcohol (ether and ester), polyoxyethylene(50) lanolin (ether and ester), acetylated polyoxyethylene (10) lanolin,polyoxyethylene (16) lanolin alcohol, acetylated polyoxyethylene (9)lanolin), alkyl polyglycosides, mono-, di- or glyceride esters (such asdiglycerine sesquioleate), acetylated monoglycerides, polyglycerols,polyglycerol esters (such as decaglycerol decaoleate, decaglyceroloctaoleate, decaglycerol tetraoleate), phospholipids (such as lecithin),mono- or diglyceride esters of citric acid, tartaric acid and lacticacid, sorbitan fatty acid esters (such as sorbitan monostearate (Span60, Crill 3), sorbitan monooleate (Arlacel 80, Span 80, Crill 4),sorbitan isosterate (Crill 6), sorbitan monolaurate (Arlacel 20, Span20, Crill 1), sorbitan trioleate (Span 85, Crill 45), sorbitantristearate (Span 65), sorbitan sesquioleate (Arlacel 83, Crill 43),sorbitan monopalmitate (Span 40, Crill 2)), polyol fatty acid esters(such as ethylene glycol distearate, ethylene glycol monostearate,diethylene glycol monostearate, propylene glycol monostearate, propyleneglycol monolaurate, polyoxyethylene (1.5) nonylphenol, polyoxyethylene(4) nonylphenol, polyoxyethylene (5) nonylphenol, polyoxyethylene (6)nonylphenol, polyoxyethylene (8) nonylphenol, polyoxyethylene (20)nonylphenol, polyoxyethylene (30) nonylphenol, polyoxyethylene (10)nonylphenol, poly(ethylene glycol) 200 distearate, poly(ethylene glycol)300 dilaurate, poly(ethylene glycol) 400 distearate, polyoxyethyleneoctylphenol, poly(ethylene glycol) 400 dilaurate, poly(ethylene glycol)400 monostearate, poly(ethylene glycol) 400 monolaurate, poly(ethyleneglycol) 4000 distearate, polyoxyethylene (10) octylphenol, poly(ethyleneglycol) 600 monostearate, Polyoxyethylene (14) nonylphenol,polyoxyethylene (24) cholesterol, polyoxyethylene (25) soyasterol,poly(ethylene glycol) 1000 monooleate, polyoxyethylene (25) propyleneglycol monostearate, poly(ethylene glycol) 1000 monolaurate,polyoxyethylene (70) dinonylphenol), glycerol fatty acid esters (such asglycerol dioleate, glycerol monoleate, glycerol monostearate, glycerolmonolaurate, polyoxyethylene (20) glycerol monostearate), sucrose fattyacid esters (such as sucrose distearate, sucrose monolaurate),polyoxyethylene sorbitan fatty acid esters (polysorbates) (such aspolyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (5) sorbitanmonooleate, polyoxyethylene (20) sorbitan monooleate (Tween 80),polyoxyethylene (40) sorbitol hexaoleate, polyoxyethylene (50) sorbitolhexaoleate, polyoxyethylene (20) sorbitan tristearate, polyoxyethylene(20) sorbitan trioleate, polyoxyethylene (20) sorbitan monostearate,polyoxyethylene (20) sorbitan monopalmitate, polyoxyethylene (20)sorbitan monolaurate (Tween 20), polysorbate 20 NF, EP, JP,poly(ethylene glycol)-20 sorbitan isostearate, poly(ethylene glycol)(20) sorbitan trioleate (Crillet 45), poly(ethylene glycol) (20)sorbitan stearate (Crillet 3 Super, Polysorbate 60), poly(ethyleneglycol) (20) sorbitan oleate (Crillet 4 Super, Polysorbate 80),poly(ethylene glycol) (20) sorbitan laurate (Crillet 2 Super,Polysorbate 40)), monoesters (such as polyoxyethylene (4) stearic acid,polyoxyethylene (8) stearic acid, polyoxyethylene (8) lauric acid,polyoxyethylene (40) stearic acid, polyoxyethylene (50) stearic acid),polyethoxylated esters of acyl acids (such as polyoxyethylene (2) octylalcohol, polyoxyethylene (4) tridecyl alcohol, polyoxyethylene (6)tridecyl alcohol, polyoxyethylene (8) tridecyl alcohol), copolymers ofpolyethylene oxide and polypropylene oxide, polyoxyethylene fatty ethers(such as polyoxyethylene fatty ethers derived from lauryl, cetyl,stearyl and oleyl alcohols, polyoxyethylene (4) lauryl ether,polyoxyethylene (23) lauryl ether (Brij 35), polyoxyethylene (2) cetylether (Brij 52), polyoxyethylene (10) cetyl ether, polyoxyethylene (20)cetyl ether (Brij 58), polyoxyethylene (2) stearyl ether (Brij 72),polyoxyethylene (10) stearyl ether, polyoxyethylene (20) stearyl ether,polyoxyethylene (2) oleyl ether, polyoxyethylene (10) oleyl ether (Brij97), polyoxyethylene (20) oleyl ether, polyoxyethylene (21) stearylether, polyoxyethylene (12) lauryl ether), fatty amides (such asN,N,-Dimethylstearamide), Polyethylene glycol ether of linear alcohol,polyoxyethylene (15) tall oil fatty acids (ester), acetylated sucrosediesters, isopropyl ester of lanolin fatty acids, polyoxyethylenesorbitol beeswax derivative, Polyoxypropylene/Polyoxyethylenecondensate, sodium oleate, polyoxyethylene (20) castor oil (ether,ester), glycerol oleate & propylene glycol (Arlacel 186) and Cremophor.

Exemplary pharmaceutical carriers also include starch, glucose, lactose,sucrose, gelatin, saline, gum acacia, keratin, urea, malt, rice flour,chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodiumchloride, dried skim milk, glycerol, propylene, glycol, water, andethanol. If desired, the carrier can also contain minor amounts ofwetting or emulsifying agents, or pH buffering agents.

Formulations for topical application can take the compositional form ofa liquid, a semisolid dosage form (e.g., a paste, a cream, a lotion, apowder, an ointment or a gel), a patch or a spray. According to someembodiments, the topical composition may be a cream or gel that can beapplied to an affected area of the skin of a subject in need thereof.Different release profiles can be achieved with different forms, such asbut not limited to controlled release, delayed release, extendedrelease, or sustained release. The topical pharmaceutical compositionmay be applied multiple times a day, once per day, or as often asneeded.

According to some embodiments, an exemplary pharmaceutical creamformulation may include: Lidocaine (local anesthetic agent), MSM(chemical driver), ethoxydiglycol (chemical driver), deionized water,polyacrylamide (a flocculant), C₁₃₋₁₄ isoparaffin (an emollient),laureth-7 (surfactant and emulsifier), propylene glycol (penetrationenhancer), triethanol amine (pH balancer), emu oil (antifungal agent),tea tree oil (antifungal agent), arnica Montana extract(anti-inflammatory agent); ethylhexylglycerin (fragrant), phenoxyethanol(bactericide), isopropyl palmitate (emollient, moisturizer, thickeningagent, anti-static), stearic acid (surfactant and softening agent),5-fluorouracil (anti-neoplastic). Any suitable excipients in thesecategories also can be used in accordance with the embodiments of thedescribed invention.

Lidocaine is a widely used local anesthetic that was first synthesizedby Lofgren in 1943 (Lofgren N, Lundqvist B (1946). Svensk KemiskTidskrift 58: 206-17). Its IUPAC name is:2-(diethylamino)-N-(2,6-dimethylphenyl)acetamide, and its CAS number is:137-58-6/73-78-9 (hydrochloride). Lidocaine is used as a topical painreliever/numbing agent in both prescription and over the counter (OTC)forms (Drug Bank. (2013, Feb. 8). Lidocaine.http://drugbank.ca/drugs/DB00281, accessed 28 Aug. 2013), may be used asan injected local anesthetic during various surgical procedures, andalso is used intravenously in certain circumstances, such as in cardiacarrest. Lidocaine also is a first line anti-arrhythmic drug when used athigh doses (Sleight P J (1990). Cardiovasc Pharmacol 16: S113-119);(Collinsworth, K. Circulation 50: 1217-30 (1974). In addition, lidocaineis often the local anesthetic of choice during intubation, minimallyinvasive surgery, and many dental procedures (Mehta P, Caiazzo A,Maloney P (1998). Anesth Prog 45: 38-41).

The effectiveness of lidocaine as a local anesthetic is distinguished byits accelerated onset of action and intermediate duration. As a result,lidocaine is suitable for infiltration, block and surface anesthesia(Alabdalla J, Hoffart L. Lidocaine.http://www.lidocaine.weebly.com/references.htm, accessed 27 Aug. 2013).While lidocaine's mechanism of action is favorable for multiple modes ofanesthesia, the ability of a formulation to allow adequate dermalpenetration has limited the utility of topical lidocaine treatments. Thestudy of cutaneous barriers to topical absorption suggests thathydrophobicity has little impact on the ability of a topically applieddrug to reach interstitial fluid (Fortenbach C R, Modjtahedi B S,Maibach H I (2008). Skin Pharmacol Physiol 21: 294-299); (Hansen S, LehrC M, Schaefer U F (2013). Adv Drug Deliv Rev 65: 251-264). However, ithas also been noted that greater lipid solubility results in increaseddiffusion through cell membranes, and thereby slowing the onset ofanesthesia (in the case of anesthetics) (Becker D E, Reed K L (2012).Anesth Prog 59: 90-102). In the case of drugs bearing charged groups, aswith the tertiary amines of lidocaine and related substances, transferefficiency into circulation is related to the pKa of the charged group,where a pKa of 7.4 or slightly below providing greater entry intoneuronal cell membranes and thus greater anesthetic efficiency. Otherstudies have indicated that dosing with other agents such asepinephrine, can increase the concentration of lidocaine in the brain(Takahashi R, Oda Y, Tanaka K, Morishima H O, Inoue K, Asada A (2006).Anesthesiol 105: 984-989). Because there appears to be a strong linearcorrelation between the concentration of a drug in serum and ininterstitial fluid, the ability to provide efficient transdermal drugdelivery has significant clinical implications (Jepps O G, Dancik Y,Anissimov Y G, Roberts M S (2013). Adv Drug Deliv Rev 65: 152-168).Indeed, several groups have reported on formulations intended to enhancetopical drug delivery (Lee P J, Ahmad N, Langer R, Mitragotri S, ShastriV P (2006). Intl J Pharmaceut 308: 33-39); (Roberts M S, Cross S E(1999). Inflammopharmacol 7: 339-50); (Osborne D W (2011). J CosmetDermatol 10: 324-9); (Otto A, Wiechers J W, Kelly C L, Hadgraft J, duPlessis J (2008). Skin Pharmacol Physiol 21: 326-334). To take advantageof the potential benefits from topical drug application, a unique,proprietary formulation of lidocaine has been developed by SambriaPharmaceutical, focusing on agents that act as the “drivers” ofcutaneous penetration. Our studies suggest that this formulation forlidocaine provides excellent results in providing anesthetic effects forlocal, acute pain.

Along with providing direct delivery to interstitial fluid, there are anumber of advantages and disadvantages to using a topical pain reliefcream. Advantages include, but are not limited to, avoidance of hepaticfirst-pass metabolism, convenience and ease of application, and theability to target a specific site of pain. Disadvantages may includeskin irritation, and also may include poor or variable permeabilitythrough the skin, which can result in insufficient therapeutic effectfor the patient (Moody M L (2010). Topical Medications in the Treatmentof Pain. New York City: McMahon Publishing).

As shown in Table 1, the amount of used deionized water would thenaccordingly be chosen in the pharmaceutical formulation such that thefinal amount w/w % will be equal to 100%:

TABLE 1 Exemplary cream formulation. Specific Ingredient Amount (w/w %)Range (w/w %) Deionized water Can be varied 1-50% Lidocaine 4.00% 1-20%MSM 3.00% 1-10% Ethoxydiglycol 1.00% 0.10-5% Polyacrylamide 6.50% 1-20%C₁₃₋₁₄ isoparaffin 6.50% 1-20% Laureth-7 6.50% 1-20% Propylene Glycol1.00% 0.10-5% Triethanolamine 0.90% 0.10-5% Emu Oil 0.25% 0.10-5% TeaTree Oil 0.20% 0.10-5% Arnica Montana Extract 0.50% 0.10-5%Ethylhexylglycerin 0.40% 0.10-5% Phenoxyethanol 0.40% 0.10-5% IsopropylPalmitate 0.20% 0.10-5% Stearic Acid 0.15% 0.05%-5% 5-fluorouracil 1.00%1.00%-5%

According to some embodiments, formulations and doses can be tailored toa subject's fat content, as some therapeutic can be lost to the fatlayer (the rate and extent of the diffusion of the therapeutic and aminobenzoate local anesthetic can vary).

The pharmaceutical composition of the described invention isadministered and dosed in accordance with Good Medical Practice's(GMP's) and guidelines provided and approved by the Food and DrugAdministration (FDA), taking into account the clinical condition of theindividual subject, the site and method of administration, scheduling ofadministration, patient age, sex, body weight, whether or not thesubject is on other medication and other factors known to medicalpractitioners. The pharmaceutically “effective amount” for purposesherein is thus determined by such considerations as are known in theart. The amount must be effective to achieve improvement including butnot limited to improved survival rate or more rapid recovery, orimprovement or elimination of symptoms and other indicators as areselected as appropriate measures by those having ordinary skill in theart.

Use of the Disclosed Compositions

According to some embodiments, the topical delivery system of thedescribed invention can be used in the manufacture of a medicament fortreating a plurality of skin conditions, disorders or diseases.Non-limiting examples of diseases or disorders that can be treated withthe pharmaceutical composition of the described invention include,without limitation, pruritus, atopic dermatitis, psoriasis, acne, skininfections, skin infestations, skin neoplasms, wounds to the skin, paincausing disorders and skin manifestations of autoimmune disorders oruses for anesthesia prior to procedures including, but not limited to,for example superficial dermal instrumentation.

According to another aspect, the described invention provides a methodfor treating a disease, disorder or condition susceptible to treatmenttopically comprising administering the topical composition describedherein to skin.

According some embodiments, the pharmaceutical composition of thedescribed invention can be administered as the pharmaceuticalformulation alone, or as an active ingredient in combination withpharmaceutically acceptable carriers, diluents, adjuvants and otherauxiliary vehicles. According to some embodiments, the subject is forexample, a warm-blooded animal, for example a mammal, including man. Thepharmaceutically acceptable carriers, diluents, adjuvants and vehicles,as well as implant carriers generally refer to inert, non-toxic solid orliquid fillers, diluents or encapsulating material not reacting with theactive ingredients of the invention.

The doses given may be as a single dose, or as multiple doses over apredetermined period stretching a plurality of days, months or years. Asused herein the term “plurality” refers to an event characterized bymore than one. According to some embodiments, the pharmaceuticalcomposition is administered multiple times at a plurality of treatmentdates, or as needed in the judgment of a treating physician.

According to some embodiments, treatment can be continuous ordiscontinuous. As used herein, the term “continuous” refers to anactivity that is unbroken and without interruption. As used herein, theterm “discontinuous” refers to an activity that is broken and withinterruption for a predetermined amount of time as judged by thetreating physician. As such, the treatment may advantageously beconducted continuously over a period of days, months, or years ordiscontinuously over a period of days, months, or years.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range is encompassed within the invention. The upper and lowerlimits of these smaller ranges which can independently be included inthe smaller ranges is also encompassed within the invention, subject toany specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either bothof those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although exemplary methods andmaterials have been described, any methods and materials similar orequivalent to those described herein can also be used in the practice ortesting of the described invention. All publications mentioned hereinare incorporated herein by reference to disclose and described themethods and/or materials in connection with which the publications arecited.

As used herein and in the appended claims, the singular form “a,” “and,”“the” include plural referents unless the context clearly dictatesotherwise. The terms “comprises,” “comprising,” “includes,” “including,”“having” and their conjugates mean “including but not limited to.” Termsand phrases used in this application, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing, the term, “including” shouldbe read as meaning “including, without limitation” or the like. Theterm, “example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof. Adjectives suchas e.g., “conventional,” “traditional,” “known” and terms of similarmeaning should not be construed as limiting the item described to agiven time period, or to an item available as of a given time, but,instead these terms should be read to encompass conventional,traditional, normal, or standard technologies that may be available,known now, or at any time in the future. Likewise, a group of itemslinked with the conjunction “and” should not be read as requiring thateach and every one of those items be present in the grouping, but rathershould be read as “and/or” unless expressly stated otherwise. Similarly,a group of items linked with the conjunction “or” should not be read asrequiring mutual exclusivity among that group, but rather should also beread as “and/or” unless expressly stated otherwise. The presence ofbroadening words and phrases such as “one or more,” “at least,” “such asbut not limited to,” or other like phrases in some instances shall notbe read to mean that the narrower case is intended or required ininstances, wherein such broadening phrases may be absent.

Additionally, for example any sequence(s) and/or temporal order ofsequence of the system and method that are described herein thisdisclosure are illustrative and should not be interpreted as beingrestrictive in nature. Accordingly, it should be understood that theprocess steps may be shown and described as being in a sequence ortemporal order, but they are not necessarily limited to being carriedout in any particular sequence or order.

Although the described invention has been described and illustratedherein with referred to some embodiments, it will be apparent to thoseof ordinary skill in the art that other embodiments may perform similarfunctions and/or achieve like results. Thus, it should be understoodthat various features and aspects of the disclosed of the disclosedembodiments can be combined with, or substituted for one another inorder to form varying modes of the disclosed invention. Many differentembodiments such as variations, adaptations, modifications, andequivalent arrangements thus fall within the scope and spirit of thedescribed invention. Although a specific composition has been described,broader invention that would include some elements are also contemplatedherein this disclosure.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the described invention. Nothingherein should be construed as an admission that the described inventionis not entitled to antedate such publication by virtue of priorinvention. Further, the dates of publication provided may be differentfrom the actual publication dates, which may be independently confirmed.

EXAMPLES

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how tomake and use the described invention, and are not intended to limit thescope of what the inventors regard as their invention nor are theyintended to represent that the experiments below are all or the onlyexperiments performed. Efforts have been made to ensure accuracy withrespect to numbers used (e.g., amounts, temperatures, etc.) but someexperimental errors and deviations should be accounted for. Unlessindicated otherwise, parts are by weight, molecular weight is weightaverage molecular weight, temperature is in degrees Centigrade, andpressure is at or near atmospheric.

Example 1 Phase 1 Clinical Study

Objectives of the Study

The primary objective of this Phase Clinical I study was to determinethe safety of topically applied NeuroMed7™ 4% lidocaine, as indicated byits uptake into blood and clearance rate and also by the occurrence oflatent adverse events.

Secondary objectives included:

-   -   estimating the effectiveness of a proprietary cream formulation;    -   determining the effect of dosage frequency on blood levels and        clearance rate;    -   among patients reporting acute pain, determining the        effectiveness of the topical cream in reducing pain, as        expressed by self-reported visual analog scale (VAS); and    -   estimating rates of absorption and distribution, and also of        metabolism by simultaneous determination of lidocaine and of        monoethylglycinexylidide (MEGX), the primary metabolite of        lidocaine.        Materials and Methods        Ethics:

The study was conducted by the clinical research unit of InsightInstitute of Neurosurgery & Neuroscience (Flint, Mich.), in accordancewith the guidelines on International Conference on HarmonisationGuidelines for Good Clinical Practice (E6[R1]) (International Conferenceon Harmonisation Guidelines for Good Clinical Practice (E6[R1]).ich.org/products/guidelines/efficacy/efficacy-single/article/good-clinical-practice.html.Accessed 13 Nov. 2013), the Code of Federal Regulations for GoodClinical Practice (21 CFR Parts 50 and 56) (US Food and DrugAdministration. FDA regulations relating to Good Clinical Practice andclinical trials.http://www.fda.gov/scienceresearch/specialtopics/runningclinicaltrials-/ucm114928.htm.Accessed 13 Nov. 2013), and the Declaration of Helsinki regarding thetreatment of human study subjects (WMA Declaration of Helsinki—Ethicalprinciples for medical research involving human subjects.http://wma.net/en/20activities/10ethics/10helsinki/. Accessed 13 Nov.2013). The clinical study protocol and informed consent form werereviewed and approved (Jul. 30, 2013) by the institutional review boardat Western Institutional Review Board (WIRB, Olympia, Wash., study20131169). All subjects signed informed consent forms prior to enrollingin the study, and were interviewed for latent adverse effects within 24h after completion of study activities. All study procedures wereperformed between Aug. 15 and Sep. 22, 2013. All subjects who registeredinto the study met the eligibility criteria that had been approved byWIRB.

Inclusion Criteria included:

-   -   Healthy individuals of both genders and any ethnic background;    -   Age≥18 years;    -   Willing to submit to venipuncture at study intervals; and    -   Ability to understand and the willingness to sign a written        informed consent.

Exclusion Criteria included:

-   -   Cardiac, hepatic, renal, pulmonary, neurological,        gastrointestinal and hematological diseases, psychiatric        disorders, and allergy to local anesthetics;    -   History of chronic disease;    -   Pregnancy;    -   Active local skin infection or skin pathological condition at        the site of administration;    -   Tattoo, surgical scar or skin condition at the site of        administration that might interfere with penetration of agent        into the skin; and    -   Currently using lidocaine or any related amide-containing agent        that might provide a false positive result in the clinical        analysis of lidocaine.        Study Drug:

The lidocaine preparation marketed as NeuroMed7™ was obtained fromSambria™ Pharmaceuticals at 4% (w/w) in a cream that includesmethylsulfonylmethane (MSM) and ethoxydiglycol in accordance with theformulation disclosed in Table 1 above.

Drug Application and Safety Sample Analysis:

The 4% lidocaine cream was provided by Sambria Pharmaceuticals(Woodstock, Ga.). Whole blood (10 mL per bleed) was collected usingstandard venipuncture into serum Vacutainer tubes (Franklin Lakes,Ill.). Following centrifugation at 1000×g for 30 min, serum wastransferred to 5 mL polypropylene tubes and snap-frozen in a dryice/ethanol slurry. Frozen samples were shipped overnight on dry ice toNMS Labs, Willow Grove, Pa. The samples were analyzed by gaschromatography, using forensic standards with a detection limit of 0.1mcg/mL for both lidocaine and MEGx, ie, 15-20-fold below the therapeuticreference range (NMS Labs, Willow Grove, Pa.)(http://www.pathology.med.umich.edu/handbook/, accessed 6 Sep. 2013).This analytical method was selected to allow quantitation ofsub-clinical levels of lidocaine and MEGx that are not captured usingstandard clinical laboratory methods (typically, fluorescencepolarization immunoassay). The selected method also will detect levelsof drug that fall within the clinical range, which is necessary toverify the relationship between dosage and physiological response.

Clinical Study Schema:

The general study plan required 2 equivalent, 1 mL doses of NeuroMed7™4% lidocaine to a subject's selected region of acute pain and drugapplication at 0 and 4 h, with schema presented in FIG. 3. As indicated,10 mL of venous blood was collected throughout the study period, at timeintervals likely to capture peak and trough levels (Greenblatt D J etal. (1985). Arch Otolaryngol 111: 2988-3000); (Baumann L S, et al.(2010). J Drugs Dermatol 9: 1500-1504). Each subject provided self-ratedpain evaluations at those same time intervals, focusing on pain at theidentified site of acute pain and of drug application, using the 1-10Visual Analog Scale (VAS) (Meier T, et al. (2003). Pain 106: 151-158).

Results and Discussion

Safety Study:

The primary goal of this Phase I study was to investigate the extent towhich lidocaine enters circulation following topical application ofNeuroMed7 4% lidocaine cream, to indicate drug safety. Blood levelsfrequently are used as an index of toxicity, particularly in the absenceof physiological signs. There are clinical signs that indicate thepresence of adverse effects due to relatively high levels of lidocaine,and also of some physiologically active degradation products, inparticular, MEGx. This study used both blood measurements, and questionsposed to study subjects on specific side effects, as indicators ofNeuroMed7™ safety.

Venous blood samples were taken prior to the initial dosing at 0 h, and1, 3, 5, 7, 9 and 11 hours following the initial (1 h) drug application,which for the last 4 samples (indicated on FIG. 3. Study Schema) alsocorresponds to 1, 3, 5 and 7 hours after the second (4 h) drugapplication. Lidocaine levels were below the detection limit of 0.1mcg/mL (μg/mL) in all blood samples. Among all samples analyzed forMEGx, only one, sample #4 for subject 16, the level of MEGx was at thedetection limit, i.e., 0.1 mcg/mL. Given that the anticipated peaklevels in blood occur between 1 and 2 hours after administration, andthe unlikelihood of consenting subjects to more frequent venipuncture,the study was designed to approximate the peak drug levels resultingfrom each lidocaine dose.

For these blood analytes, among 239 serum samples that were analyzed,only 1 displayed a measurable result, despite our use of an analyticalmethod that is 15-20-fold more sensitive than typical clinicallaboratory methods that are calibrated for therapeutic levels rangingfrom 1.5 to 5.0 mcg/mL(http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/8382.Accessed 19 Nov. 2013); (Becker D E, Reed K L (2012). Anesth Prog 59:90-102). The one detectable sample was collected 1 h after the secondlidocaine administration, and results from the additive effect of thesubject's initial dose along with the 4 h dose. It is concluded fromtoxicology studies that the doses of lidocaine in NeuroMed7™, used asindicated in the FDA monograph, are well below the levels of concern.

Toxic levels of lidocaine typically occur at levels greater than 6.0mcg/mL, with symptoms including central nervous excitation,lightheadedness, dizziness, tinnitus, confusion, and blurred or doublevision (Valdes R et al. (1998). Clin Chem 44(5): 1096-1099). Within 24 hafter concluding the study, as well as during their immediateparticipation, subjects were contacted with questions regarding sideeffects. There were no such reports of adverse effects related to drugactivity. Three subjects did experience slight lightheadedness thatappeared to result from venipuncture, as they were felt after each blooddraw. It is concluded from the measured blood levels, as well asclinical signs, that the subjects in this study expressed no symptoms oflidocaine toxicity.

Studies of Efficacy:

The central data used to describe efficacy was the 10-point VAS. Whilethis measure is subjective, the study subjects were requestedspecifically to be consistent in their pain estimates. The mean initialpain score at 0 h (+/−SD) was 4.0 (1.3). The reported pain reduction forall subjects and at all time points was significant and transient, asexpected (FIG. 4). The subjective nature self-scored pain scales, notedwith VAS, as well with other pain scales, results in considerablesubject-to-subject variation. This is particularly dramatic when lookingat the variation (expressed as standard deviation) in the average painreduction within the study cohort (FIG. 5). Having such a broad rangeresults from the inherent subjectivity of the initial pain score,compounded by the subjective estimate in efficacy. Regardless ofspecific numbers, NeuroMed7™ had a positive effect in reducing acutepain.

Related to the individual reduction in pain is the extent of painreduction, based on the initial score. This analysis groups the cohortby percent of pain reduction, asking how many subjects experiencedvarious level of pain relief. As indicated in FIG. 6, many subjectsexperienced a high level of pain relief, with a total of 28 of 34subjects having relief at 50% or better.

Effect latency, or the time before maximum pain relief, was anothermeasure of interest. Again, there are inter-subject variables that mayimpact the time before maximum pain effect. Indeed, having 2 doses oflidocaine imposes on each subject 2 pharmacokinetic curves that may, insome individuals and depending on the time between dosing, be additive.Nonetheless, it is instructive that 9 subjects expressed maximum painrelief at the 1 hour point, with the extent of relief presenting analmost exponential decay following that point (FIG. 7).

CONCLUSION

Thirty-four subjects were enrolled (20 women, 14 men). Prior to drugadministration, neither lidocaine nor MEGx was found in the serum of anyof the subjects. Serum concentrations for both analytes were below thelimit of detection for the analytical method (0.1 mcg/mL), with theexception of one male subject, whose 5-hour MEGx level was reported asdetectable at the detection limit of 0.1 mcg/mL. Possible adversereactions among study subjects, which included central nervous systemand cardiovascular effects, were not reported. Initial self-reportedacute pain levels by VAS ranged from 1 to 8, with a mean (+/−SD) priorto drug administration of 4.33 (1.72); pain levels subsequent tolidocaine application were at 1 h: 2.33 (1.8); 3 h: 2.14 (2.16); 5 h:1.88 (2.09); 7 h: 1.73 (2.29); 9 h: 1.67 (2.23); and 11 h: 2.07 (1.69).The study population achieved reductions in the initial level of acutepain of 41% (1 h), 54% (3 h), 59% (5 h), 64% (7 h), 62% (9 h) and 57%(11 h). Pain reduction was 50% or greater among 82% of subjects (28 of34), with the time elapsed to reach maximal pain reduction being 1 h for27% of subjects, followed by 21% (3 h), 18% (5 h), 9% (7 h), 12% (9 h),and 6% (11 h).

This Phase 1 study provides direct evidence demonstrating the safety ofNeuroMed7™ 4% lidocaine cream when used as indicated in the OTCmonograph, ie, 1 mL dosing at least 4 h apart, with a maximum of 2 dosesper day. No sufficiently high blood levels of lidocaine or MEGx thatwould indicate toxicity was detected, and there were no reportedclinical signs of overdose. Our analysis of efficacy demonstratedpositive responses whose broad variation is attributed to the locus ofpain and pain history, as well as other uncontrolled variables. Despitethe spread in response, the use of NeuroMed7™ as indicated provideseffective topical pain relief, while presenting little in the way ofsecondary adverse effects. Lidocaine is an agent that can bephysiologically damaging at doses much higher than used in this study.However, when used as indicated, NeuroMed7™ provides a broad margin ofsafety to the user.

Thus the lidocaine formulation presented no measurable safety issues,either in measurable serum levels (since the highest measurable levelwas 0.10 mcg/mL, whereas toxicity is indicated at >5 mcg/mL), or inphysiological response, and was effective among the majority of thesesubjects.

While the present invention has been described with reference to thespecific embodiments thereof it should be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of theinvention. In addition, many modifications may be made to adopt aparticular situation, material, composition of matter, process, processstep or steps, to the objective spirit and scope of the presentinvention. All such modifications are intended to be within the scope ofthe claims appended hereto.

What is claimed is:
 1. A method of delivering a pharmaceuticalcomposition topically that is effective to reduce systemic side effectsof an amino benzoate local anesthetic agent comprising applyingtopically directly to skin of a subject over an area of pain atherapeutic amount of the pharmaceutical composition comprising: (i) theamino benzoate local anesthetic agent in an amount of 1-20% w/w, (ii) apenetration enhancer comprising a penetration enhancing amount of anethoxydiglycol component in an amount of 0.10-5% w/w and amethylsulfonylmethane (MSM) component in an amount of 1-10% w/w; and(iii) a liposome depot component wherein the pharmaceutical compositionis effective: (a) to deeply penetrate the skin of the subject; (b) toremain in the skin and block nerve signals affecting sensation of pain,and (c) to provide pain relief.
 2. The method according to claim 1,wherein the amount of the amino benzoate local anesthetic agent in thebloodstream is less than a therapeutic amount.
 3. The method accordingto claim 1, wherein the liposome depot component is effective tofacilitate controlled or delayed type release of the amino benzoatelocal anesthetic agent.
 4. The method according to claim 1, wherein theliposome depot component is a polymer.
 5. The method according to claim1, wherein the liposome comprises a phosphatidyl choline, cholesteroland at least one anionic or cationic phospholipid.
 6. The methodaccording to claim 5, wherein the liposome comprises a pharmaceuticallyacceptable salt of the amino benzoate local anesthetic agent.
 7. Themethod according to claim 1, wherein the liposome depot componentcomprises a polymer.
 8. The method according to claim 1, wherein theliposome depot component is a polymersome.
 9. The method of claim 1,comprising the amino benzoate local anesthetic agent in an amount of 4%w/w, a penetration enhancer comprising a penetration enhancing amount ofan ethoxydiglycol component in an amount of 1% w/w, and amethylsulfonylmethane (MSM) component in an amount of 3% w/w.